bluuebunny/crossref_metadata_2025 huggingface dataset:
Genetic Exceptionalism and Legislative Pragmatism
Authors: Rothstein Mark A.
Published: May 2007

One of the most important and contentious policy issues surrounding genetics is whether genetic information should be treated separately from other medical information. The view that genetics raises distinct issues is what Thomas Murray labeled “genetic exceptionalism,” borrowing from the earlier term “HIV exceptional-ism.” The issue of whether the use of genetic information should be addressed separately from other health information is not merely an academic concern, however. Since the Human Genome Project began in 1990, nearly every state has enacted legislation prohibiting genetic discrimination in health insurance; two-thirds of the states have enacted laws prohibiting genetic discrimination in employment, and other state laws have been enacted dealing with genetic discrimination in life insurance, genetic privacy, and genetic testing. Bills in Congress also would prohibit genetic discrimination in health insurance and employment.
Decentralized Stabilization of Neural Network Linearly Interconnected Systems via T-S Fuzzy Control
Authors: Hsiao Feng-Hsiag , Liang Yew-Wen , Xu Sheng-Dong , Lee Gwo-Chuan
Published: May 2007

The stabilization problem is considered in this study for a neural-network (NN) linearly interconnected system that consists of a number of NN models. First, a linear difference inclusion (LDI) state-space representation is established for the dynamics of each NN model. Then, based on the LDI state-space representation, a stability criterion in terms of Lyapunov’s direct method is derived to guarantee the asymptotic stability of closed-loop NN linearly interconnected systems. Subsequently, according to this criterion and the decentralized control scheme, a set of Takagi-Sugeno (T-S) fuzzy controllers is synthesized to stabilize the NN linearly interconnected system. Finally, a numerical example with simulations is given to demonstrate the concepts discussed throughout this paper.
Kernel and Offspring Concepts for the Stability Robustness of Multiple Time Delayed Systems (MTDS)
Authors: Sipahi Rifat , Olgac Nejat
Published: May 2007

A novel treatment for the stability of linear time invariant (LTI) systems with rationally independent multiple time delays is presented in this paper. The independence of delays makes the problem much more challenging compared to systems with commensurate time delays (where the delays have rational relations). We uncover some wonderful features for such systems. For instance, all the imaginary characteristic roots of these systems can be found exhaustively along a set of surfaces in the domain of the delays. They are called the “kernel” surfaces (curves for two-delay cases), and it is proven that the number of the kernel surfaces is manageably small and bounded. All possible time delay combinations, which yield an imaginary characteristic root, lie either on this kernel or its infinitely many “offspring” surfaces. Another hidden feature is that the root tendencies along these surfaces exhibit an invariance property. From these outstanding characteristics an efficient, exact, and exhaustive methodology results for the stability assessment. As an added uniqueness of this method, the systems under consideration do not have to be stable for zero delays. Several example case studies are presented, which are prohibitively difficult, if not impossible to solve using any other peer methodology known to the authors.
Dynamic Stability of Open-Loop Hopping
Authors: Cham Jorge G. , Cutkosky Mark R.
Published: May 2007

Simulations and physical robots have shown that hopping and running are possible without sensory feedback. However, stable behavior is often limited to a certain range of the parameters of the open-loop system. Even the simplest of hopping systems can exhibit unstable behavior that results in unpredictable nonperiodic motion as system parameters are adjusted. This paper analyzes the stability of a simplified vertical hopping model driven by an open-loop, feedforward motor pattern. Periodic orbits of the resulting hybrid system are analyzed through a generalized formula for the system’s Poincare Map and Jacobian. The observed behavior is validated experimentally in a physical pneumatically actuated hopping machine. This approach leads to observations on the stability of this and similar systems, revealing inherent limitations of open-loop hopping and providing insights that can inform the design and control of dynamic legged robots capable of rapid and robust locomotion.
Time Series Based Structural Damage Detection Algorithm Using Gaussian Mixtures Modeling
Authors: Krishnan Nair K. , Kiremidjian Anne S.
Published: May 2007

In this paper, a time series based detection algorithm is proposed utilizing the Gaussian Mixture Models. The two critical aspects of damage diagnosis that are investigated are detection and extent. The vibration signals obtained from the structure are modeled as autoregressive moving average (ARMA) processes. The feature vector used consists of the first three autoregressive coefficients obtained from the modeling of the vibration signals. Damage is detected by observing a migration of the extracted AR coefficients with damage. A Gaussian Mixture Model (GMM) is used to model the feature vector. Damage is detected using the gap statistic, which ascertains the optimal number of mixtures in a particular dataset. The Mahalanobis distance between the mixture in question and the baseline (undamaged) mixture is a good indicator of damage extent. Application cases from the ASCE Benchmark Structure simulated data have been used to test the efficacy of the algorithm. This approach provides a useful framework for data fusion, where different measurements such as strains, temperature, and humidity could be used for a more robust damage decision.
Development of Experimental Genetic Tools for
Campylobacter fetus
Authors: Kienesberger Sabine , Gorkiewicz Gregor , Joainig Martina M. , Scheicher Sylvia R. , Leitner Eva , Zechner Ellen L.
Published: May 2007

Molecular analysis of the virulence mechanisms of the emerging pathogen
Campylobacter fetus
has been hampered by the lack of genetic tools. We report the development and functional analysis of
Escherichia coli
-
Campylobacter
shuttle vectors that are appropriate for
C. fetus
. Some vectors were constructed based on the known
Campylobacter coli
plasmid pIP1455 replicon, which confers a wide host range in
Campylobacter
spp. Versatility in directing gene expression was achieved by introducing a strong
C. fetus
promoter. The constructions carry features necessary and sufficient to detect the expression of phenotypic markers, including molecular reporter genes in both subspecies of
C. fetus
, while retaining function in
C. jejuni
. The capacity to express several gene products from different vectors in a single host can be advantageous but requires distinct plasmid replicons. To this end, replication features derived from a cryptic plasmid of
C. fetus
subsp.
venerealis
strain 4111/108, designated pCFV108, were adapted for a compatible series of constructions. The substitution of the
C. coli
replication elements reduced vector size while apparently limiting the host range to
C. fetus
. The complementation of a ciprofloxacin-resistant mutant phenotype via vector-driven
gyrA
expression was verified. Cocultivation demonstrated that shuttle vectors based on the pCFV108 replicon were compatible with pIP1455 replication functions, and the stable maintenance of two plasmids in a
C. fetus
subsp.
venerealis
host over several months was observed. The application of both vector types will facilitate the investigation of the genetics and cellular interactions of the emerging pathogen
C. fetus
.
Physiological and Molecular Responses of
Lactuca sativa
to Colonization by
Salmonella enterica
Serovar Dublin
Authors: Klerks M. M. , van Gent-Pelzer M. , Franz E. , Zijlstra C. , van Bruggen A. H. C.
Published: May 2007

This paper describes the physiological and molecular interactions between the human-pathogenic organism
Salmonella enterica
serovar Dublin and the commercially available mini Roman lettuce cv. Tamburo. The association of
S. enterica
serovar Dublin with lettuce plants was first determined, which indicated the presence of significant populations outside and inside the plants. The latter was evidenced from significant residual concentrations after highly efficient surface disinfection (99.81%) and fluorescence microscopy of
S. enterica
serovar Dublin in cross sections of lettuce at the root-shoot transition region. The plant biomass was reduced significantly compared to that of noncolonized plants upon colonization with
S. enterica
serovar Dublin. In addition to the physiological response, transcriptome analysis by cDNA amplified fragment length polymorphism analysis also provided clear differential gene expression profiles between noncolonized and colonized lettuce plants. From these, generally and differentially expressed genes were selected and identified by sequence analysis, followed by reverse transcription-PCR displaying the specific gene expression profiles in time. Functional grouping of the expressed genes indicated a correlation between colonization of the plants and an increase in expressed pathogenicity-related genes. This study indicates that lettuce plants respond to the presence of
S. enterica
serovar Dublin at physiological and molecular levels, as shown by the reduction in growth and the concurrent expression of pathogenicity-related genes. In addition, it was confirmed that
Salmonella
spp. can colonize the interior of lettuce plants, thus potentially imposing a human health risk when processed and consumed.
RNA Interference Mutant Induction In Vivo Demonstrates the Essential Nature of Trypanosome Flagellar Function during Mammalian Infection
Authors: Griffiths Samantha , Portman Neil , Taylor Philip R. , Gordon Siamon , Ginger Michael L. , Gull Keith
Published: May 2007

We demonstrate that trypanosomes compromised in flagellar function are rapidly cleared from infected mice. Analysis of the PFR2 bloodstream RNA interference mutant revealed that defective cell motility occurred prior to cytokinesis failure. This validation provides a paradigm for the flagellum as a target for future assays and interventions against this human pathogen.
Development of a Highly Efficient Gene Targeting System Induced by Transient Repression of
YKU80
Expression in
Candida glabrata
Authors: Ueno Keigo , Uno Jun , Nakayama Hironobu , Sasamoto Kaname , Mikami Yuzuru , Chibana Hiroji
Published: May 2007

In the pathogenic yeast
Candida glabrata
, gene targeting to generate knockouts and “knockins” is a potentially powerful method for the analysis of gene function. Its importance increased after the
C. glabrata
genome sequence project, but progress in the field is hampered by inefficient mechanisms for gene targeting. With the use of 40-bp homologous flanking DNA, no gene targeting was identified. To address this issue,
YKU80
was disrupted, leading to an increase in targeting efficiency of 5.1% using 40-bp flanking homologous DNA. To harness the beneficial effects of
YKU80
inactivation on gene targeting frequency without incurring any negative effects, such as synthetic sickness or lethality, we developed a new system whereby the expression of
YKU80
was restored following a transient knockdown of expression during transformation. Strains used for this new system carried a
SAT1
flipper in the
YKU80
promoter region, which was used to repress expression during transformation but was spontaneously excised from the locus after the transformation. By using this strain, DNA damage induced by methyl methane sulfonate, H
2
O
2
, UV irradiation, and hydroxyurea before and during gene targeting was evaluated and the mutation rate of
URA3
was determined. No significant effects of the
SAT1
flipper on these processes have been identified. After the
SAT1
flipper is excised, a 34-bp FLP recombination target sequence is left in the promoter region. However, the levels of mRNA transcription were restored and no difference in the survival ratio in vivo compared to that with the
YKU80
wild-type strain was identified.
Phosphorylated AbsA2 Negatively Regulates Antibiotic Production inStreptomyces coelicolorthrough Interactions with Pathway-Specific Regulatory Gene Promoters
Authors: McKenzie Nancy L. , Nodwell Justin R.
Published: May 2007

The AbsA two-component signal transduction system, comprised of the sensor kinase AbsA1 and the response regulator AbsA2, acts as a negative regulator of antibiotic production inStreptomyces coelicolor, for which the phosphorylated form of AbsA2 (AbsA2∼P) is the agent of repression. In this study, we used chromatin immunoprecipitation to show that AbsA2 binds the promoter regions ofactII-ORF4,cdaR, andredZ, which encode pathway-specific activators for actinorhodin, calcium-dependent antibiotic, and undecylprodigiosin, respectively. We confirm that these interactions also occur in vitro and that the binding of AbsA2 to each gene is enhanced by phosphorylation. Induced expression ofactII-ORF4 andredZin the hyperrepressiveabsA1mutant (C542) brought about pathway-specific restoration of actinorhodin and undecylprodigiosin production, respectively. Our results suggest that AbsA2∼P interacts with as many as four sites in the region that includes theactII-ORF4 promoter. These data suggest that AbsA2∼P inhibits antibiotic production by directly interfering with the expression of pathway-specific regulators of antibiotic biosynthetic gene clusters.
Performance of the HerpeSelect (Focus) and Kalon Enzyme-Linked Immunosorbent Assays for Detection of Antibodies against Herpes Simplex Virus Type 2 by Use of Monoclonal Antibody-Blocking Enzyme Immunoassay and Clinicovirological Reference Standards in Brazil
Authors: Nascimento Maria Claudia , Ferreira Suzete , Sabino Ester , Hamilton Ingrid , Parry John , Pannuti Claudio S. , Mayaud Philippe
Published: May 2007

A total of 586 serum samples were used to evaluate the performance of type-specific herpes simplex virus type 2 (HSV-2) commercial enzyme-linked immunosorbent assays (ELISAs) by using the monoclonal antibody-blocking enzyme immunoassay (MAb-EIA) and a clinicovirological panel as reference standards. The Kalon and HerpeSelect ELISAs had similar sensitivities (93.5% and 93.8% compared with the results obtained by MAb-EIA, respectively, and 100% for both ELISAs compared with the results obtained with a clinicovirological panel). The Kalon ELISA had a higher specificity (96.5% and 96.8% compared with the results obtained by MAb-EIA and with a clinicovirological panel, respectively) than the HerpeSelect ELISA (86.9% and 94% compared with the results obtained by MAb-EIA and with a clinicovirological panel, respectively). A higher cutoff significantly improved the specificity of the HerpeSelect ELISA.
Rare Case of
Nocardia asteroides
Pericarditis in a Human Immunodeficiency Virus-Infected Patient
Authors: Jinno Sadao , Jirakulaporn Tanawat , Bankowski Matthew J. , Kim Wesley , Wong Russell
Published: May 2007

Nocardia asteroides
was isolated after prolonged culture from the pericardial fluid of a human immunodeficiency virus-infected patient. The lengthy duration required for culture growth and identification of this
N. asteroides
isolate affected both initial therapeutic decisions and patient management. A proposed algorithm for the microbiological workup of pericardial fluid for possible
Nocardia
spp. is described in an effort to improve the timeliness of results.
Establishment of a Poliovirus Oral Infection System in Human Poliovirus Receptor-Expressing Transgenic Mice That Are Deficient in Alpha/Beta Interferon Receptor
Authors: Ohka Seii , Igarashi Hiroko , Nagata Noriyo , Sakai Mai , Koike Satoshi , Nochi Tomonori , Kiyono Hiroshi , Nomoto Akio
Published: May 2007

Poliovirus (PV) is easily transferred to humans orally; however, no rodent model for oral infections has been developed because of the alimentary tract's low sensitivity to the virus. Here we showed that PV is inactivated by the low pH of the gastric contents in mice. The addition of 3% NaHCO
3
to the viral inoculum increased the titer of virus reaching the small intestine through the stomach after intragastric inoculation of PV. Transgenic mice (Tg) carrying the human PV receptor (hPVR/CD155) gene and lacking the alpha/beta interferon receptor (IFNAR) gene (hPVR-Tg/
Ifnar
KO) were sensitive to the oral administration of PV with 3% NaHCO
3
, whereas hPVR-Tg expressing IFNAR were much less sensitive. The virus was detected in the epithelia of the small intestine and proliferated in the alimentary tract of hPVR-Tg/
Ifnar
KO. By the ninth day after the administration of a virulent PV, the mice had died. These results suggest that IFNAR plays an important role in determining permissivity in the alimentary tract as well as the generation of virus-specific immune responses to PV via the oral route. Thus, hPVR-Tg/
Ifnar
KO are considered to be the first oral infection model for PV, although levels of anti-PV antibodies were not elevated dramatically in serum and intestinal secretions of surviving mice when hPVR-Tg/
Ifnar
KO were administered an attenuated PV.
Conserved Changes in Envelope Function during Human Immunodeficiency Virus Type 1 Coreceptor Switching
Authors: Pastore Cristina , Nedellec Rebecca , Ramos Alejandra , Hartley Oliver , Miamidian John L. , Reeves Jacqueline D. , Mosier Donald E.
Published: May 2007

We studied the evolution of human immunodeficiency virus type 1 (HIV-1) envelope function during the process of coreceptor switching from CCR5 to CXCR4. Site-directed mutagenesis was used to introduce most of the possible intermediate mutations in the envelope for four distinct coreceptor switch mutants, each with a unique pattern of CCR5 and CXCR4 utilization that extended from highly efficient use of both coreceptors to sole use of CXCR4. Mutated envelopes with some preservation of entry function on either CCR5- or CXCR4-expressing target cells were further characterized for their sensitivity to CCR5 or CXCR4 inhibitors, soluble CD4, and the neutralizing antibodies b12-IgG and 4E10. A subset of mutated envelopes was also studied in direct CD4 or CCR5 binding assays and in envelope-mediated fusion reactions. Coreceptor switch intermediates displayed increased sensitivity to CCR5 inhibitors (except for a few envelopes with mutations in V2 or C2) that correlated with a loss in CCR5 binding. As use of CXCR4 improved, infection mediated by the mutated envelopes became more resistant to soluble CD4 inhibition and direct binding to CD4 increased. These changes were accompanied by increasing resistance to the CXCR4 inhibitor AMD3100. Sensitivity to neutralizing antibody was more variable, although infection of CXCR4-expressing targets was generally more sensitive to neutralization by both b12-IgG and 4E10 than infection of CCR5-expressing target cells. These changes in envelope function were uniform in all four series of envelope mutations and thus were independent of the final use of CCR5 and CXCR4. Decreased CCR5 and increased CD4 binding appear to be common features of coreceptor switch intermediates.
Climatic effects on caterpillar fluctuations in northern hardwood forests
Authors: Reynolds Lindsay V. , Ayres Matthew P. , Siccama Thomas G. , Holmes Richard T.
Published: May 2007

Fluctuations in the abundance of Lepidoptera are common but inadequately understood. Here we show that caterpillar abundance in the White Mountains of New Hampshire has fluctuated by >20-fold from 1986 to 2005. We report tests of three possible causes: (i) extreme winter cold; (ii) long, warm summers; and (iii) interannual variation in tree growth, which tends to correlate with phytochemistry. Caterpillar fluctuations from summers t to t + 1 were uncorrelated or negatively correlated with minimum air temperature during the intervening winter (does not support the first cause), but were positively correlated with thermal sum during summer t (r = 0.49–0.56) (supports the second cause). There was limited interannual variation in the radial growth of two dominant tree species ( Acer saccharum Marsh. and Betula alleghaniensis Britt.) and no correlation with caterpillar fluctuations (refutes the third cause). Thermal sum might influence caterpillar fluctuations through direct effects on insect development, indirect effects on susceptibility to natural enemies, and (or) indirect effects on plant-insect interactions; the mechanisms are of particular interest because thermal sums have been increasing since local records began in 1957 (r = 0.41–0.45). In hardwoods forests of the northeastern United States, there is some broad-scale driver related to summer temperatures that generates fluctuations in caterpillar abundance, which influences herbivory as well as higher level consumers, such as insectivorous birds.
The role of stand density on growth efficiency, leaf area index, and resin flow in southwestern ponderosa pine forests
Authors: McDowell Nate G. , Adams Henry D. , Bailey John D. , Kolb Thomas E.
Published: May 2007

We examined the response of growth efficiency (GE), leaf area index (LAI), and resin flow (RF) to stand density manipulations in ponderosa pine ( Pinus ponderosa Dougl. ex Laws.) forests of northern Arizona, USA. The study used a 40 year stand density experiment including seven replicated basal area (BA) treatments ranging from 7 to 45 m2·ha–1. Results were extended to the larger region using published and unpublished datasets on ponderosa pine RF. GE was quantified using basal area increment (BAI), stemwood production (NPPs), or volume increment (VI) per leaf area (Al) or sapwood area (As). GE per Al was positively correlated with BA, regardless of numerator (BAI/Al, NPPs/Al, and VI/Al; r2 = 0.84, 0.95, and 0.96, respectively). GE per As exhibited variable responses to BA. Understory LAI increased with decreasing BA; however, total (understory plus overstory) LAI was not correlated with BA, GE, or RF. Opposite of the original research on this subject, resin flow was negatively related to GE per Al because Al/As ratios decline with increasing BA. BAI, and to a lesser degree BA, predicted RF better than growth efficiency, suggesting that the simplest measurement with the fewest assumptions (BAI) is also the best approach for predicting RF.
Changes in fungal communities in evergreen broad-leaved forests across a gradient of urban to rural areas in JapanThis article is one of a selection of papers published in the Special Forum on Towards Sustainable Forestry — The Living Soil: Soil Biodiversity and Ecosystem Function.
Authors: Ochimaru Takehiko , Fukuda Kenji
Published: May 2007

We investigated the structure of the fungal community of evergreen broad-leaved forests dominated by evergreen oak ( Castanopsis sieboldii or Quercus myrsinaefolia ) through surveying sporocarps in urban, suburban, and rural areas of the Kanto District, Japan. In a 4 year census, 132 species of fungi were recorded and classified into five groups on the basis of growth substrate: 22 litter decomposers, 39 wood rotters, 10 rotted-wood decomposers, 23 humus decomposers, and 38 ectomycorrhizal species. A long-term survey of fungi revealed lower species richness and diversity of ectomycorrhizal fungi in the urban and suburban forest than in the rural forest. The low species diversity of ectomycorrhizal fungi in the urban forest was related to low species richness of Amanitaceae and a high frequency of some Russulaceae species such as Russula japonica . In contrast, species richness and abundance of litter decomposers and wood rotters were higher in the urban forest than in the rural forest. The uneven litter distribution on soil surfaces in the mountainous rural forest may have caused the lower species richness of litter decomposers. Rotted-wood decomposers and humus decomposers showed no significant differences among the three types of forest.
Structure of soil microbial communities in sugi plantations and seminatural broad-leaved forests with different land-use historyThis article is one of a selection of papers published in the Special Forum on Towards Sustainable Forestry — The Living Soil: Soil Biodiversity and Ecosystem Function.
Authors: Matsushita Miho , Ito Satoshi , Meguro Sadatoshi , Kawachi Shinsaku
Published: May 2007

Phospholipid fatty acid profiles were used to evaluate microbial community composition in different soil layers of sugi ( Cryptomeria japonica (L.f.) D. Don) plantations and seminatural secondary forests in southeastern Kyushu, Japan. These forests had previously been utilized as meadows or coppices. Principal components analysis and canonical correspondence analysis of the phospholipid fatty acid data demonstrated differences in microbial community structure between current vegetation (sugi plantations or seminatural forests) in the FH layer. In contrast, differences between the previous land-use types (meadows or coppices) were detected through variation in the soil microbial community structure in the upper part of the A layer (0–5 cm). However, in the deeper part of the A layer (5–10 cm), the influence of the previous land-use history on soil microbial community structure was weak and the influence of the current vegetation could be detected. In the 0–5 cm part of the A layer, the organic matter was correlated with the microbial community structure. However, it cannot be assumed that these soil chemical characteristics were the principal factors responsible for separation of the microbial communities based on previous land-use history because the difference in chemical characteristics between the sites was small.
COMPARISON OF GAS SLIP MODELS WITH SOLUTIONS OF LINEARIZED BOLTZMANN EQUATION AND DIRECT SIMULATION OF MONTE CARLO METHOD
Authors: TANG G. H. , HE Y. L. , TAO W. Q.
Published: May 2007

Analytical solutions of the Navier–Stokes equation based on a locally fully-developed flow assumption with various gas slip models are presented and comparisons for velocity profile, flow rate, friction factor, and pressure distribution are performed. The effect of the second-order coefficient in the slip boundary condition becomes significant as the Knudsen number increases. Most slip models are limited to slip regime or marginally transition regime and break down around Kn = 0.1 while Sreekanth's model, followed by Mitsuya's model, gives a good agreement with the linearized Boltzmann solutions from slip regime up to Kn = 2 for flow rate and friction factor predictions. These two models should be of great use for slip flow analysis in micro-electro-mechanical systems (MEMS) and, in particular, in situations where the flow rate and flow resistance are of interest.
MODELING THE CO-OCCURRENCE PRINCIPLES OF THE CONSONANT INVENTORIES: A COMPLEX NETWORK APPROACH
Authors: MUKHERJEE ANIMESH , CHOUDHURY MONOJIT , BASU ANUPAM , GANGULY NILOY
Published: May 2007

Speech sounds of the languages all over the world show remarkable patterns of co-occurrence. In this work, we attempt to automatically capture the patterns of co-occurrence of the consonants across languages and at the same time figure out the nature of the force leading to the emergence of such patterns. For this purpose we define a weighted network where the consonants are the nodes and an edge between two nodes (read consonants) signify their co-occurrence likelihood over the consonant inventories. Through this network we identify communities of consonants that essentially reflect their patterns of co-occurrence across languages. We test the goodness of the communities and observe that the constituent consonants frequently occur in such groups in real languages also. Interestingly, the consonants forming these communities reflect strong correlations in terms of their features, which indicate that the principle of feature economy acts as a driving force towards community formation. In order to measure the strength of this force we propose a theoretical information definition of feature economy and show that indeed the feature economy exhibited by the consonant communities are substantially better than that of those where the consonant inventories had evolved just by chance.
MODELING TIME SERIES DATA OF REAL SYSTEMS
Authors: AHALPARA DILIP P. , PARIKH JITENDRA C.
Published: May 2007

Dynamics of complex systems is studied by first considering a chaotic time series generated by Lorenz equations and adding noise to it. The trend (smooth behavior) is separated from fluctuations at different scales using wavelet analysis and a prediction method proposed by Lorenz is applied to make out of sample predictions at different regions of the time series. The prediction capability of this method is studied by considering several improvements over this method. We then apply this approach to a real financial time series. The smooth time series is modeled using techniques of non linear dynamics. Our results for predictions suggest that the modified Lorenz method gives better predictions compared to those from the original Lorenz method. Fluctuations are analyzed using probabilistic considerations.
MANY-AGENT CONTROLLED MULTI-PLAYER QUANTUM SECRET SHARING SCHEME
Authors: MAN ZHONG-XIAO , XIA YUN-JIE , ZHANG ZHAN-JUN
Published: May 2007

In this paper, we propose a scheme of many-agent controlled multi-player quantum secret sharing. The players are some filed performers to implement a task by using the secret messages from a supremo, while the agents may be the players' superiors who hold the controls also from the supremo and can manipulate the task by using the controls. In the scheme only Bell states are employed and need to be identified, which implies that it is more easily implemented with today's technique.
ENTANGLEMENT OF A SINGLE-MODE CAVITY QED OF A RAMAN INTERACTION
Authors: ABDEL-ATY M. , AL-SHOWAIKH F. , HASSAN S. S.
Published: May 2007

We investigate the entanglement of a degenerate Raman process involving two degenerate Rydberg energy levels of an atom interacting with a single-mode cavity field. We use the concurrence as an entanglement measure and show that long living entanglement can be obtained for certain choices of the system parameters.
CAN ENTANGLEMENT BE EXTRACTED FROM MANY BODY SYSTEMS?
Authors: DE CHIARA GABRIELE , BRUKNER ČASLAV , MASSIMO PALMA G. , FAZIO ROSARIO , VEDRAL VLATKO
Published: May 2007

Some thermodynamical properties of solids, such as heat capacity and magnetic susceptibility, have recently been shown to be linked to the amount of entanglement in a solid. Until now, however, it was not clear whether this entanglement can be used as a resource in quantum information theory. Here we show that this entanglement is physical, demonstrating the principles of its extraction from a typical spin chain by scattering two particles off the system. Moreover, we show how to simulate this process using present-day optical lattice technology.
ENTANGLEMENT PROPERTIES OF A STRONGLY DRIVEN RESONANT JAYNES–CUMMINGS SYSTEM
Authors: CASAGRANDE F. , LULLI A.
Published: May 2007

We describe the unitary dynamics and the entanglement properties of a system where a cavity field mode is resonantly coupled to one or two two-level atoms that are strongly driven in the cavity by a coherent field. The cavity field and one atom prepared in pure states always entangle, except when atoms are maximally polarized. The entanglement is maximum for atoms in the upper or lower state and for interaction times in the strong coupling regime. Two atoms, though correlated via the cavity field, do not entangle if the field is not accessible to measurements as in the microwave domain. However, in the optical regime, a null measurement of the cavity field can conditionally prepare an atom pair in a maximally entangled state.
QUANTUM COMPUTATIONAL SCHEMES GENERATED BY k-BOSON ALGEBRAS
Authors: RAFFA FRANCESCO A. , RASETTI MARIO
Published: May 2007

It is shown that a multiboson (k-boson) algebra can be conveniently utilized to generate a k-dimensional computational basis. The single qukit logical operators are given ∀k and two different constructions of the CNOT gate are presented.
DYNAMICAL ENTANGLEMENT IN NON-RELATIVISTIC ELASTIC SCATTERING
Authors: HARSHMAN N. L.
Published: May 2007

This article considers dynamical entanglement in non-relativistic particle scattering. Three questions are explored: what kinds of entanglement occur in this system, how do global symmetries constrain entanglement, and how do the boundary conditions of scattering affect dynamical entanglement? First, a simple model of scattering spin systems is considered, then the full system is discussed.
DEVELOPMENT OF SUPERCONDUCTING SINGLE-PHOTON DETECTORS AT I.N.Ri.M.
Authors: TARALLI E. , RAJTERI M. , MONTICONE E. , PORTESI C.
Published: May 2007

We are developing single-photon detectors employing superconducting-transition-edge sensors (TESs). TESs are fabricated both with Ti and proximity bilayers of Ti / Au and the characterisitcs of the two films are compared. In the visible-near infrared spectral region, the photon absorption occurs directly in the film and the quantum efficiency of the detector is limited by the reflection losses at the film surface, which are around 60%. For many applications, like quantum cryptography, these losses are too high. In a previous paper [Nucl. Instr. Meth. A559(2) (2006) 757–759], we presented a way to reduce the detector reflectance for two projects based on the deposition of a few layers of amorphous silicon-nitrogen alloys. In this paper, we report some experimental data at low temperature relative to those projects. We will also show how to minimize the detector reflectance simultaneously for three telecommunication wavelengths and for a new continuum band.
SQUEEZING OSCILLATIONS OF A QUANTIZED FIELD INTERACTING WITH PAIR OF COLD ATOMS VIA INTENSITY-DEPENDENT COUPLING
Authors: KOROLI V. I.
Published: May 2007

We study the interaction between a single-mode electromagnetic field and a pair of indistinguishable two-level atoms via the intensity-dependent coupling. This problem is equivalent to the equidistant three-level atom with equal dipole moment matrix transition elements between the adjacent levels. The exact analytical solution for the atom–field state-vector is obtained assuming that at the initial moment the field is in the Holstein–Primakoff SU (1,1) coherent state. The quantum statistical and squeezing properties of the field are investigated. The results obtained are compared with those for the single two-level atom obtained by Buzek. We observe that the exact periodicity of the field squeezing that takes place in the case of the single two-level atom is violated in the case of the pair of cold atoms. That is, the exact periodicity of the physical quantities can be destroyed only if the radiation field interacts with a system of more than one two-level atom.
Reverse electron flow-induced ROS production is attenuated by activation of mitochondrial Ca2+-sensitive K+ channels
Authors: Heinen André , Aldakkak Mohammed , Stowe David F. , Rhodes Samhita S. , Riess Matthias L. , Varadarajan Srinivasan G. , Camara Amadou K. S.
Published: May 2007

Mitochondria generate reactive oxygen species (ROS) dependent on substrate conditions, O2 concentration, redox state, and activity of the mitochondrial complexes. It is well known that the FADH2-linked substrate succinate induces reverse electron flow to complex I of the electron transport chain and that this process generates superoxide (O2•−); these effects are blocked by the complex I blocker rotenone. We demonstrated recently that succinate + rotenone-dependent H2O2 production in isolated mitochondria increased mildly on activation of the putative big mitochondrial Ca2+-sensitive K+ channel (mtBKCa) by low concentrations of 1,3-dihydro-1-[2-hydroxy-5-(trifluoromethyl)phenyl]-5-(trifluoromethyl)-2 H-benzimidazol-2-one (NS-1619). In the present study we examined effects of NS-1619 on mitochondrial O2 consumption, membrane potential (ΔΨm), H2O2 release rates, and redox state in isolated guinea pig heart mitochondria respiring on succinate but without rotenone. NS-1619 (30 μM) increased state 2 and state 4 respiration by 26 ± 4% and 14 ± 4%, respectively; this increase was abolished by the BKCa channel blocker paxilline (5 μM). Paxilline alone had no effect on respiration. NS-1619 did not alter ΔΨm or redox state but decreased H2O2 production by 73% vs. control; this effect was incompletely inhibited by paxilline. We conclude that under substrate conditions that allow reverse electron flow, matrix K+ influx through mtBKCa channels reduces mitochondrial H2O2 production by accelerating forward electron flow. Our prior study showed that NS-1619 induced an increase in H2O2 production with blocked reverse electron flow. The present results suggest that NS-1619-induced matrix K+ influx increases forward electron flow despite the high reverse electron flow, and emphasize the importance of substrate conditions on interpretation of effects on mitochondrial bioenergetics.
Imbalance between endothelium-derived relaxing and contracting factors in mesenteric arteries from aged OLETF rats, a model of Type 2 diabetes
Authors: Matsumoto Takayuki , Kakami Mika , Noguchi Eri , Kobayashi Tsuneo , Kamata Katsuo
Published: May 2007

We investigated whether the balance between endothelium-derived relaxing factors (EDRFs) and endothelium-derived contracting factors (EDCFs) might be altered in mesenteric arteries from aged Otsuka Long-Evans Tokushima Fatty (OLETF) rats (a Type 2 diabetic model) [vs. age-matched control Long-Evans Tokushima Otsuka (LETO) rats]. ACh-induced relaxation was impaired in the OLETF group, and a tendency for the relaxation to reverse at high ACh concentrations was observed in both groups. This tendency was abolished by indomethacin. Nitric oxide- and/or endothelium-derived hypolarizing factor-mediated relaxation and the protein expressions of phospho-endothelial nitric oxide synthase (Ser1177) and extracellular superoxide dismutase were also reduced in OLETF. An ACh-induced contraction was observed at higher ACh concentrations in the presence of NG-nitro-l-arginine (l-NNA) but was greater in OLETF rats. This contraction in OLETF rats was reduced by cyclooxygenase (COX) inhibitors and by prostanoid-receptor antagonists. The ACh-induced productions of thromboxane A2 and PGE2 were greater in OLETF than LETO rats, as were the mesenteric artery COX-1 and COX-2 protein expressions. Moreover, tert-butyl hydroperoxide ( t-BOOH) (membrane-permeant oxidant) induced a concentration-dependent contraction that was greater in OLETF rats. The t-BOOH-mediated contraction was increased both by l-NNA and by endothelium removal in LETO but not OLETF rats, suggesting that a negative modulatory role of the endothelium was lost in OLETF rats. These results suggest that an imbalance between EDRFs and EDCFs may be implicated in the endothelial dysfunction seen in aged OLETF mesenteric arteries, and may be attributable to increased oxidative stress.
H2O2activation of HSP25/27 protects desmin from calpain proteolysis in rat ventricular myocytes
Authors: Blunt Bradford C. , Creek Aaron T. , Henderson DeAnna C. , Hofmann Polly A.
Published: May 2007

Ischemia-reperfusion-induced Ca2+overload results in activation of calpain-1 in the heart. Calpain-dependent proteolysis contributes to myocardial dysfunction and cell death. Previously, preischemic treatment with low doses of H2O2was shown to improve postischemic function and reduce myocardial infarct size. Our aim was to determine the mechanism by which H2O2protects the heart. We hypothesized that H2O2causes the activation of p38 MAPK which initiates translocation of heat shock protein 25/27 (HSP25/27) to the myofilament Z disk. We further hypothesized that HSP25/27 shields structural proteins, particularly desmin, from calpain-induced proteolysis. To address this hypothesis, we first determined that an ischemia-reperfusion-induced decrease in desmin content could be blocked by H2O2pretreatment of hearts from rats. We next determined that ventricular myocytes that underwent Ca2+overload also demonstrated a calpain-dependent disruption of desmin that could be reduced by H2O2/p38 MAPK activation. Furthermore, myocytes acutely treated with H2O2exhibited a decrease in cleavage of desmin upon exposure to exogenous calpain-1 compared with myocytes not pretreated with H2O2. The H2O2-induced attenuation of desmin degradation by calpain-1 was blocked by inhibition of p38 MAPK. In a final series of experiments, we demonstrated that cardiac myofilaments exposed to recombinant phosphorylated HSP27, but not nonphosphorylated HSP27, had a significant reduction in the calpain-induced degradation of desmin compared with non-HSP27-treated myofilaments. These findings are consistent with the hypothesis that H2O2-induced activation of p38 MAPK and subsequent HSP25/27 translocation attenuates desmin degradation brought about by calpain-1 activation in ischemia-reperfused hearts.
Regulation of collagen synthesis by inhibitory Smad7 in cardiac myofibroblasts
Authors: Wang Baiqiu , Omar Amer , Angelovska Tatjana , Drobic Vanja , Rattan Sunil G. , Jones Stephen C. , Dixon Ian M. C.
Published: May 2007

Transforming growth factor-β1 (TGF-β1) signal and downstream Smads play an important role in tissue fibrosis and matrix remodeling in various etiologies of heart failure. Inhibitory Smad7 (I-Smad7) is an inducible regulatory Smad protein that antagonizes TGF-β1 signal mediated via direct abrogation of R-Smad phosphorylation. The effect of ectopic I-Smad7 on net collagen production was investigated using hydroxyproline assay. Adenovirus-mediated I-Smad7 gene (at 100 multiplicity of infection) transfer was associated with significant decrease of collagen synthesis in the presence and absence of TGF-β1 in primary rat cardiac myofibroblasts. In I-Smad7-infected cells, we also observed the ablation of TGF-β1-induced R-Smad2 phosphorylation vs. LacZ controls. Overdriven I-Smad7 was associated with significantly increased expression of immunoreactive 65-kDa matrix metalloproteinase-2 (MMP-2) protein in culture medium of myofibroblast compared with LacZ-infected cells. Expression of the 72-kDa MMP-2 variant, e.g., the inactive form, was not altered by exogenous I-Smad7 transfection/overexpression. Furthermore, I-Smad7 overexpression was associated with a significant increase and decrease in expression of p27 and phospho-Rb protein, respectively, as well as reduced [3H]thymidine incorporation vs. Ad-LacZ-infected controls. We suggest that negative modulation of R-Smad phosphorylation by ectopic I-Smad7 may contribute to the downregulation of collagen in cardiac myofibroblasts and may suppress the proliferation of these cells. Thus treatments targeting the collagen deposition by overexpression of I-Smad7 may provide a new therapeutic strategy for cardiac fibrosis.
Age-related changes in lamin A/C expression in cardiomyocytes
Authors: Afilalo Jonathan , Sebag Igal A. , Chalifour Lorraine E. , Rivas Daniel , Akter Rahima , Sharma Kamal , Duque Gustavo
Published: May 2007

Lamin A and C (A/C) are type V intermediate filaments that form the nuclear lamina. Lamin A/C mutations lead to reduced expression of lamin A/C and diverse phenotypes such as familial cardiomyopathies and accelerated aging syndromes. Normal aging is associated with reduced expression of lamin A/C in osteoblasts and dermal fibroblasts but has never been assessed in cardiomyocytes. Our objective was to compare the expression of lamin A/C in cardiomyocytes of old (24 mo) versus young (4 mo) C57Bl/6J mice using a well-validated mouse model of aging. Lamin B1 was used as a control. Immunohistochemical and immunofluorescence analyses showed reduced expression of lamin A/C in cardiomyocyte nuclei of old mice (proportion of nuclei expressing lamin A/C, 9% vs. 62%, P < 0.001). Lamin A/C distribution was scattered peripherally and perinuclear in old mice, whereas it was homogeneous throughout the nuclei in young mice. Western blot analyses confirmed reduced expression of lamin A/C in nuclear extracts of old mice (ratio of lamin A/C to B1, 0.6 vs. 1.2, P < 0.01). Echocardiographic studies showed increased left ventricular wall thickness with preserved cavity size (concentric remodeling), increased left ventricular mass, and a slight reduction in fractional shortening in old mice. This is the first study to show that normal aging is associated with reduced expression and altered distribution of lamin A/C in nuclei of cardiomyocytes.
In vitro and in vivo kinetic handling of nitrite in blood: effects of varying hemoglobin oxygen saturation
Authors: Blood Arlin B. , Power Gordon G.
Published: May 2007

Growing evidence suggests that nitrite, acting via reduction to nitric oxide by deoxyhemoglobin, may play an important role in local control of blood flow during hypoxia. To investigate the effect of hypoxia (65 Torr arterial Po2) on the kinetic properties of nitrite, a bolus injection of sodium nitrite (10 mg/kg iv) was given to normoxic or hypoxic newborn lambs, and the time course of plasma nitrite and methemoglobin (MetHb) concentrations was measured. The in vivo kinetics of nitrite disappearance from plasma were biphasic and were not affected by hypoxia. Changes in MetHb, a product of the nitrite-hemoglobin reaction, also did not differ with the level of oxygenation. Hypoxia potentiated the hypotensive effects of nitrite on pulmonary and systemic arterial pressures. The disappearance of nitrite from plasma was equivalent to the increase in MetHb on a molar basis. In contrast, nitrite metabolism in sheep blood in vitro resulted in more than one MetHb per nitrite equivalent under mid- and high-oxygenation conditions: oxyhemoglobin (HbO2) saturation = 50.3 ± 1.7% and 97.0 ± 1.3%, respectively. Under the low-oxygenation condition (HbO2saturation = 5.2 ± 0.9%), significantly less than 1 mol of MetHb was produced per nitrite equivalent, indicating that a significant portion of nitrite is metabolized through pathways that do not produce MetHb. These data support the idea that the vasodilating effects of nitrite are potentiated under hypoxic conditions due to the reduction of nitrite to nitric oxide by deoxyhemoglobin.
The role of α-, β-, and γ-ENaC subunits in distal lung epithelial fluid absorption induced by pulmonary edema fluid
Authors: Elias Nael , Rafii Bijan , Rahman Muhammad , Otulakowski Gail , Cutz Ernest , O'Brodovich Hugh
Published: May 2007

Edema fluid (EF) increases epithelial Na+ transport by rat fetal distal lung epithelia (FDLE) and induces net lung fluid absorption in fetal mouse lung explants [Rafii B, Gillie DJ, Sulowski C, Hannam V, Cheung T, Otulakowski G, Barker PM, O'Brodovich H. J Physiol (Lond) 544: 537–548, 2002]. We now show that EF increases fluid absorption across monolayers of rat FDLE in a dose-dependent manner. To study the role of subunits of the epithelial Na+ channel (ENaC) in the phenomena, we cultured explants from the distal lungs of 16-day gestational age wild-type (WT) or α-, β-, or γ-ENaC knockout or heterozygote (HT) mice. WT explants cultured in media continuously expanded over time as a result of net fluid secretion. In contrast, when explants were exposed to EF for 24 h, net fluid absorption occurred. EF-exposed explants had normal histology, but marked changes were seen after Triton X-100 or staurosporine exposure. Transmission electron microscopy showed EF promoted lamellar body formation and abundant surfactant in the explants' lumens. EF-induced changes in explant size were similar in α-ENaC knockout, WT, and HT littermate fetal lung explants ( P > 0.05). In contrast, EF's effect was attenuated in β- and γ-ENaC knockouts ( P < 0.05) vs. WT and HT littermate fetal lung explants. EF exposure slightly decreased or had no effect on mRNA levels for α-ENaC in various mouse genotypes but decreased expression of β- and γ-ENaC subunit mRNAs ( P < 0.01) across all genotype groups. We conclude that β- and γ-, but not α-, ENaC subunits are essential for EF to exert its maximal effect on net fluid absorption by distal lung epithelia.