bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of Innate Defense against a Paramyxovirus Is Mediated by RIG-I and TLR7 and TLR8 in a Cell-Type-Specific Manner
Authors: Melchjorsen Jesper , Jensen Søren B. , Malmgaard Lene , Rasmussen Simon B. , Weber Friedemann , Bowie Andrew G. , Matikainen Sampsa , Paludan Søren R.
Published: September 2005

Recognition of pathogens by the innate immune system is mediated by pattern recognition receptors (PRRs), which recognize specific molecular structures of the infectious agents and subsequently trigger expression of genes involved in host defense. Toll-like receptors (TLRs) represent a well-characterized class of membrane-bound PRRs, and the RNA helicase retinoic acid inducible gene I (RIG-I) has recently been described as a novel cytoplasmic PRR recognizing double-stranded RNA (dsRNA). Here we show that activation of signal transduction and induction of cytokine expression by the paramyxovirus Sendai virus is dependent on virus replication and involves PRRs in a cell-type-dependent manner. While nonimmune cells relied entirely on recognition of dsRNA through RIG-I for activation of an antiviral response, myeloid cells utilized both the single-stranded RNA sensing TLR7 and TLR8 and dsRNA-dependent mechanisms independent of RIG-I, TLR3, and dsRNA-activated protein kinase R to trigger this response. Therefore, there appears to be a large degree of cell-type specificity in the mechanisms used by the host to recognize infecting viruses.
Cleavage of Human Cytomegalovirus Protease pUL80a at Internal and Cryptic Sites Is Not Essential but Enhances Infectivity
Authors: Loveland Amy N. , Chan Chee-Kai , Brignole Edward J. , Gibson Wade
Published: September 2005

The cytomegalovirus (CMV) maturational protease, assemblin, contains an “internal” (I) cleavage site absent from its homologs in other herpesviruses. Blocking this site for cleavage did not prevent replication of the resulting I
−
mutant virus. However, cells infected with the I
−
virus showed increased amounts of a fragment produced by cleavage at the nearby “cryptic” (C) site, suggesting that its replication may bypass the I-site block by using the C site as an alternate cleavage pathway. To test this and further examine the biological importance of these cleavages, we constructed two additional virus mutants—one blocked for C-site cleavage and another blocked for both I- and C-site cleavage. Infectivity comparisons with the parental wild-type virus showed that the I
−
mutant was the least affected for virus production, whereas infectivity of the C
−
mutant was reduced by ≈40% and when both sites were blocked virus infectivity was reduced by nearly 90%, providing the first evidence that these cleavages have biological significance. We also present and discuss evidence suggesting that I-site cleavage destabilizes assemblin and its fragments, whereas C-site cleavage does not.
Induction and Utilization of an ATM Signaling Pathway by Polyomavirus
Authors: Dahl Jean , You John , Benjamin Thomas L.
Published: September 2005

Progression from G1to S is essential for polyomavirus DNA replication and depends on the interaction of large T with the retinoblastoma gene product pRb. This virus-induced replication pathway is accompanied by p53 activation resembling a DNA damage response (12). We sought to determine whether this pathway depends in part on activation of the ATM (ataxiatelangiectasiamutated) kinase and whether the virus gains advantages from this pathway beyond that of entry into S. We show that polyomavirus infection activates the S- and G2-phase checkpoints in primary as well as established mouse cells. Infected cells undergo a prolonged S phase compared to uninfected serum-stimulated cells and show no evidence of a G2→M transition before lytic death ensues. Infection is accompanied by increases in ATM activity in vitro and in the level of ATM-S1981-P in vivo. The incubation of infected cells with caffeine, a known ATM inhibitor, did not block entry into S but reduced the rate of viral compared to cellular DNA synthesis. Importantly, caffeine lowered the yields of viral DNA an average of 3- to 6-fold and those of infectious virus by as much as 10-fold. Virus yields were 10-fold lower in ATM−/−p53−/−than in ATM+/+p53−/−mouse embryo fibroblasts, indicating a p53-independent role of ATM in productive infection. Replacement of the normal SMC1 (structuralmaintenance ofchromosomes, or cohesin) protein, a critical ATM substrate in the DNA repair pathway, with its phosphorylation mutant SMC1S957AS966Aalso lowered virus yields by roughly 90%. We suggest that polyomavirus activates and utilizes a component(s) of an ATM pathway of DNA repair to prolong S phase and aid its own replication.
Oxadiazols: a New Class of Rationally Designed Anti-Human Immunodeficiency Virus Compounds Targeting the Nuclear Localization Signal of the Viral Matrix Protein
Authors: Haffar Omar , Dubrovsky Larisa , Lowe Richard , Berro Reem , Kashanchi Fatah , Godden Jeffrey , Vanpouille Christophe , Bajorath Jürgen , Bukrinsky Michael
Published: September 2005

Despite recent progress in anti-human immunodeficiency virus (HIV) therapy, drug toxicity and emergence of drug-resistant isolates during long-term treatment of HIV-infected patients necessitate the search for new targets that can be used to develop novel antiviral agents. One such target is the process of nuclear translocation of the HIV preintegration complex. Previously we described a class of arylene bis(methylketone) compounds that inhibit HIV-1 nuclear import by targeting the nuclear localization signal (NLS) in the matrix protein (MA). Here we report a different class of MA NLS-targeting compounds that was selected using computer-assisted drug design. The leading compound from this group, ITI-367, showed potent anti-HIV activity in cultures of T lymphocytes and macrophages and also inhibited HIV-1 replication in ex vivo cultured lymphoid tissue. The virus carrying inactivating mutations in MA NLS was resistant to ITI-367. Analysis by real-time PCR demonstrated that the compound specifically inhibited nuclear import of viral DNA, measured by two-long terminal repeat circle formation. Evidence of the existence of this mechanism was provided by immunofluorescent microscopy, using fluorescently labeled HIV-1, which demonstrated retention of the viral DNA in the cytoplasm of drug-treated macrophages. Compounds inhibiting HIV-1 nuclear import may be attractive candidates for further development.
Human Herpesvirus 6 Open Reading Frame U14 Protein and Cellular p53 Interact with Each Other and Are Contained in the Virion
Authors: Takemoto Masaya , Koike Masato , Mori Yasuko , Yonemoto Sayoko , Sasamoto Yumi , Kondo Kazuhiro , Uchiyama Yasuo , Yamanishi Koichi
Published: September 2005

A mass spectroscopic analysis of proteins from human herpesvirus 6 (HHV-6)-infected cells showed that the HHV-6 U14 protein coimmunoprecipitated with the tumor suppressor p53. The binding of U14 to p53 was verified by coimmunoprecipitation experiments in both Molt-3 cells infected with HHV-6 and 293 cells cotransfected with U14 and p53 expression vectors. Indirect immunofluorescence assays (IFAs) showed that by 18 h postinfection (hpi) U14 localized to the dot-like structures observed in both the nucleus and cytoplasm where p53 was partly accumulated. Despite Northern blotting evidence that U14 follows late kinetics, the U14 protein was detected immediately after infection (at 3 hpi) by IFA. In addition, by Western blotting, U14 was detected at 0 hpi or in the presence of cycloheximide which completely abolished the expression of IE1 protein. In addition to U14, p53 was detected at 0 hpi although it was not detected in mock-infected cells. Furthermore, both U14 and p53 were clearly detected in the viral particles by Western blotting and immunoelectron microscopy, supporting the idea that U14 and p53 are incorporated into virions. Our study provides the first evidence of the incorporation of cellular p53 into viral particles and suggests that p53 may play an important role in viral infection.
Complete Nucleotide Sequence of Polyomavirus SA12
Authors: Cantalupo Paul , Doering Adrienne , Sullivan Christopher S. , Pal Achintya , Peden K. W. C. , Lewis Andrew M. , Pipas James M.
Published: September 2005

The
Polyomaviridae
have small icosahedral virions that contain a genome of approximately 5,000 bp of circular double-stranded DNA. Polyomaviruses infect hosts ranging from humans to birds, and some members of this family induce tumors in test animals or in their natural hosts. We report the complete nucleotide sequence of simian agent 12 (SA12), whose natural host is thought to be
Papio ursinus
, the chacma baboon. The 5,230-bp genome has a genetic organization typical of polyomaviruses. Sequences encoding large T antigen, small t antigen, agnoprotein, and the viral capsid proteins VP1, VP2, and VP3 are present in the expected locations. We show that, like its close relative simian virus 40 (SV40), SA12 expresses microRNAs that are encoded by the late DNA strand overlapping the 3′ end of large T antigen coding sequences. Based on sequence comparisons, SA12 is most closely related to BK virus (BKV), a human polyomavirus. We have developed a real-time PCR test that distinguishes SA12 from BKV and the other closely related polyomaviruses JC virus and SV40. The close relationship between SA12 and BKV raises the possibility that these viruses circulate between human and baboon hosts.
Pseudomyxoma peritonei: unusual origin from an ovarian mature cystic teratoma: Figure 1
Authors: Pranesh N , Menasce L P , Wilson M S , O’Dwyer S T
Published: September 2005

Pseudomyxoma peritonei (PMP) is classified into pathologically and prognostically distinct categories, such as disseminated peritoneal adenomucinosis (DPAM) and peritoneal mucinous carcinomatosis. There is overwhelming evidence that DPAM arises from a mucinous adenoma of the appendix. The one exception to this is the presentation of a mature ovarian cystic teratoma as PMP where the appendix is normal. This report describes such a case and discusses the presentation, histopathology, and treatment options.
A practical approach to the clinical diagnosis of Ewing’s sarcoma/primitive neuroectodermal tumour and other small round cell tumours sharing EWS rearrangement using new fluorescence in situ hybridisation probes for EWSR1 on formalin fixed, paraffin wax embedded tissue
Authors: Yamaguchi U , Hasegawa T , Morimoto Y , Tateishi U , Endo M , Nakatani F , Kawai A , Chuman H , Beppu Y , Endo M , Kurotaki H , Furuta K
Published: September 2005

Background:Over 90% of Ewing’s sarcoma/primitive neuroectodermal tumour (ES/PNET) cases have the t(11;22) chromosomal rearrangement, which is also found in other small round cell tumours, including desmoplastic small round cell tumour (DSRCT) and clear cell sarcoma (CCS). Although this rearrangement can be analysed by fluorescence in situ hybridisation (FISH) using routinely formalin fixed, paraffin wax embedded (FFPE) tissues when fresh or frozen tissues are not available, a sensitive and convenient detection method is needed for routine clinical diagnosis.

Aims:To investigate the usefulness of newly developed probes for detecting EWS rearrangement resulting from chromosomal translocations using FISH and FFPE tissue in the clinical diagnosis of ES/PNET, DSRCT, and CCS.

Methods:Sixteen ES/PNETs, six DSRCTs, and six CCSs were studied. Three poorly differentiated synovial sarcomas, three alveolar rhabdomyosarcomas, and three neuroblastomas served as negative controls. Interphase FISH analysis was performed on FFPE tissue sections with a commercially available EWSR1 (22q12) dual colour, breakapart rearrangement probe.

Results:One fused signal and one split signal of orange and green, demonstrating rearrangement of the EWS gene, was detected in 14 of 16 ES/PNETs, all six DRSCTs, and five of six CCSs, but not in the negative controls.

Conclusions:Interphase FISH using this newly developed probe is sensitive and specific for detecting the EWS gene on FFPE tissues and is of value in the routine clinical diagnosis of ES/PNET, DSRCT, and CCS.
Melanoma inhibitor of apoptosis protein is expressed differentially in melanoma and melanocytic naevus, but similarly in primary and metastatic melanomas
Authors: Gong J , Chen N , Zhou Q , Yang B , Wang Y , Wang X
Published: September 2005

Background:Malignant melanoma is highly resistant to current treatments. The inhibitor of apoptosis protein (IAP) family member, melanoma IAP (ML-IAP), is overexpressed in some melanoma cell lines, rendering them resistant to apoptotic signals. Targeting ML-IAP is a promising approach to treating melanoma. However, the status of ML-IAP expression in human melanoma tissues and the difference in expression between melanoma and melanocytic naevus are not known.

Aims:To investigate these issues.

Methods:ML-IAP expression in 48 archived patient samples (34 melanomas and 14 dermal naevi) was assessed by immunohistochemistry and by in situ hybridisation and reverse transcription polymerase chain reaction (RT-PCR) assays developed for the study.

Results:Expression of ML-IAP was detected in 47.6–70.6% (10 of 21 to 24 of 34) of the melanomas, varying with detection methods. The expression rate in melanoma was much higher than that in melanocytic naevus (10.0–21.4%; one of 10 to three of 14). No significant difference was seen between primary and secondary melanomas. ML-IAP expression rates assessed by the three methods were in agreement.

Conclusions:The ML-IAP expression rate in archived melanoma tissues is around 50–70%, with no difference between primary and secondary melanomas. A small number of dermal naevi (∼ 20%) also expressed ML-IAP.
STRAD in Peutz-Jeghers syndrome and sporadic cancers
Authors: de Leng W W J , Keller J J , Luiten S , Musler A R , Jansen M , Baas A F , de Rooij F W M , Gille J J P , Menko F H , Offerhaus G J A , Weterman M A J
Published: September 2005

Background/Aims:LKB1is a tumour suppressor gene that is associated with Peutz-Jeghers syndrome (PJS), a rare autosomal dominant cancer predisposition syndrome. However, germline mutations in theLKB1gene are found in only about 60% of patients with PJS, suggesting the existence of a second PJS gene. TheSTRADgene, encoding an LKB1 interacting protein that activates LKB1, which subsequently leads to polarisation of cells, is an interesting candidate for a second PJS gene and a potential tumour suppressor gene in sporadic carcinomas.

Methods:The involvement of STRAD in 42 PJS associated tumours (sporadic lung, colon, gastric, and ovarian adenocarcinomas) was studied using loss of heterozygosity (LOH) analysis of eight microsatellite markers on chromosome 17, includingTP53,BRCA1, andSTRADmarkers.

Results:Loss of the marker near theSTRADlocus was seen in 13 of 29 informative cases, including all gastric adenocarcinomas. Specific LOH of theSTRADmarker was found in four of 29 informative cases. For these patients all exons and exon–intron boundaries of theSTRADgene were sequenced, but no somatic mutations were identified. Furthermore, no germlineSTRADmutations were found in 10 patients with PJS and family members withoutLKB1germline mutation.

Conclusions:Despite the frequent occurrence of LOH in theSTRADregion, these results indicate that inactivation of theSTRADgene is not essential in the sporadic adenocarcinomas studied, although it is possible thatSTRADmay be inactivated in different ways. In addition, no evidence was found for the hypothesis that STRAD is a second PJS susceptibility gene.
Ontogeny of dive performance in pup and juvenile Steller sea lions in Alaska
Authors: Pitcher Kenneth W , Rehberg Michael J , Pendleton Grey W , Raum-Suryan Kimberly L , Gelatt Thomas S , Swain Una G , Sigler Michael F
Published: September 2005

Development of competent diving ability is critical to obtaining nutritional independence in marine mammals such as Steller sea lions (SSLs), Eumetopias jubatus (Schreber, 1776). We studied diving performance in pup (75) and juvenile (36) SSLs using satellite data recorders. In general, dives by SSLs were brief and shallow. Overall, 82.3% of dives were <2 min long and 86.9% of dives were <10 m deep. Long (>5 min) and deep dives (>100 m) constituted only 2.49% and 0.77%, respectively, of total dives. We used linear mixed-effects models to investigate the relationships between the response variables maximum-daily-depth, time-at-depth, mean-dive-duration, dive rate, and time-at-sea and the predictor variables age, sex, population (eastern and western Alaska populations), time-of-day, and month-of-year. All response variables except dive rate were positively related (P < 0.05) to age. Dive rate declined (P < 0.001) with age. Time-of-day, month, population, sex, and some first-order interactions were all significantly (P < 0.05) related to some measure of diving performance. With large samples we were able to identify significant relationships between the response variables and the predictor variables, even though the total amount of variation explained by the models was low, because most dives were short and shallow regardless of age, sex, population, time-of-day, or month-of-year. Depths and durations of dives by juvenile animals increased throughout the range of ages studied and were similar to or greater than those previously reported for juveniles and adult females. We expect maximum depths and durations to continue to increase with age until body mass plateaus at about 10 years of age. Therefore, we expect older animals to be more efficient foragers, as they would have greater aerobic dive limits as well as more experience locating and capturing prey.
Effects of breeding density and plumage coloration on mate guarding and cuckoldry in blue grosbeaks (Passerina caerulea)
Authors: Estep Laura K , Mays, Jr. Herman , Keyser Amber J , Ballentine Barbara , Hill Geoffrey E
Published: September 2005

For species in which females mate outside of the pair bond, selection should favor male mate-guarding behaviors that minimize investment in genetically unrelated offspring. Mate guarding may impose costs by diverting time and energy from activities such as foraging and seeking extra-pair copulations, so males should adjust their mate-guarding behavior according to the risk of cuckoldry. In this study, we investigated cuckoldry and mate guarding in the blue grosbeak (Passerina caerulea L., 1758), a socially monogamous, territorial songbird. Fifty-three percent of nestlings were extra-pair, and 70% of nests had at least one extra-pair fertilization. Males with dull plumage coloration were more likely to be cuckolded than males with more brightly colored plumage, but duller males did not guard their mates more. Instead, males appeared to adjust mate-guarding behavior according to the attractiveness of neighbors. Males with more brightly colored neighbors guarded their mates more intensely than males with fewer colorful neighbors. These observations suggest that in the blue grosbeak, mate guarding is a context-dependent strategy that is adjusted according to the density and ornamentation of neighboring males.
Demography and decline of the Mentasta caribou herd in Alaska
Authors: Jenkins Kurt J , Barten N L
Published: September 2005

We evaluated population trends in the Mentasta caribou (Rangifer tarandus (L., 1758)) herd in Wrangell – St. Elias National Park and Preserve, Alaska, from 1990 to 1997 and determined factors contributing to its decline. We postulated that predation-related mortality of adult females and juveniles was the proximate cause of the decline, and that survival of juvenile caribou reflected interactions with winter severity, calving distribution, timing of births, density of caribou, and physical condition of neonates at birth. The population declined at its greatest rate from 1990 to 1993 (r = –0.32) and at a lower rate from 1994 to 1997 (r = –0.09). Recruitment (number of calves/100 females during September) averaged 4/100 during the rapid population decline from 1990 to 1993 and 13/100 from 1994 to 1997. Parturition rate of adult females ranged from 65% to 97%. Survival of adult females and juveniles ranged from 0.77 to 0.86 and from 0.00 to 0.22, respectively. Approximately 43%, 59%, and 79% of all juvenile mortality occurred by 1, 2, and 4 weeks of age, respectively. We confirmed predation-related mortality as the primary proximate cause of population decline, with gray wolves (Canis lupus L., 1758), bears (species of the genus Ursus L., 1758), and other predators accounting for 57%, 38%, and 5%, respectively, of all juvenile mortality, and bears causing disproportionate mortality among 0- to 1-week-old neonates. We supported the hypotheses that timing of birth and habitat conditions at the birth site, particularly mottled snow patterns, affected vulnerability and survival of neonates, and birth mass affected survival of juveniles through summer. We speculate that the population will continue to decline before reaching a low-density equilibrium that is sustained by density-dependent changes in the functional responses of predators.
The quantitative effects of population density and winter weather on the body condition of white-tailed deer (Odocoileus virginianus) in Nova Scotia, Canada
Authors: Garroway Colin J , Broders Hugh G
Published: September 2005

Understanding the underlying mechanisms that cause variation in survival and the reproductive success of animals is essential for predicting variation in population parameters. To gain an understanding of the effects of density and winter weather severity on white-tailed deer, Odocoileus virginianus (Zimmermann, 1780), we examined the effects of current-year deer density and cumulative weekly average values for snow depth, rainfall, and the number of degrees below –15 °C until the time of death, as well as cumulative effects of density and snow depth over the previous one and two winters, on the body condition of adult females, adult males, and fawns. Model selection using Akaike's Information Criterion and multi-model inference suggested that snow depth was the best predictor of body condition for all three age/sex groups. Winter rainfall was the next most influential predictor for adult females and adult males but was not important in determining fawn body condition. Temperature had the least influence on the body condition of all three age/sex groups. Deer density during the winter of death had minimal effects for all groups and we found no evidence that cumulative multiyear variables influenced body condition. We hypothesize that cohort variation may better explain previous findings showing effects of multiyear variables. A model for estimating the proportion of animals in poor body condition for each age/sex group is presented.
Hibernating black bears have blood chemistry and plasma amino acid profiles that are indicative of long-term adaptive fasting
Authors: Lohuis T D , Beck T D.I , Harlow H J
Published: September 2005

Blood samples were drawn from six black bears (Ursus americanus Pallas, 1780) active in the summer and six others in early and late hibernation. Plasma urea:creatinine ratios and concentrations of amino acids, alanine aminotransferase, and aspartate aminotransferase dropped during the winter denning season, suggesting a decreased protein breakdown. Fifteen amino acids (3 branched chain and 12 glucogenic) were lower in the early winter than in the summer, but 6 of these amino acids rose back to summer levels by the late denning season. Hydroxyproline and glycine were also elevated during late winter, suggesting an increase in collagen breakdown. This profile suggests a dynamic process of adaptive fasting and protein conservation during the winter with a mobilization of non-myofibrilar collagen and perhaps smooth muscle protein reserves to augment a potential but slight increased breakdown of skeletal muscle during the late winter.
QUANTUM GENETIC ALGORITHM METHOD IN SELF-CONSISTENT ELECTRONIC STRUCTURE CALCULATIONS OF A QUANTUM DOT WITH MANY ELECTRONS
Authors: ŞAHİN MEHMET , ATAV ÜLFET , TOMAK MEHMET
Published: September 2005

In this study, we have calculated energy levels of an N-electron quantum dot. For this purpose, we have used two different techniques, matrix diagonalization and quantum genetic algorithm, to obtain simultaneous solutions of the coupled Schrödinger and Poisson equation in the Hartree approximation. We have determined single particle energy levels, total energy, chemical potential and capacitive energy. We have also compared the results, demonstrated the applicability of QGA to many-electron quantum systems and evaluated its effectiveness.
A LATTICE BOLTZMANN APPROACH FOR IMMISCIBLE FLUIDS WITH VERY DIFFERENT VISCOSITIES
Authors: MISICI LUCIANO , PALPACELLI SILVIA
Published: September 2005

In this article, a lattice Boltzmann model for two immiscible fluids with same density but a large viscosity difference is developed. The effect of surface tension is included. An indicator function is used to model the interface motion and is updated by a lattice Boltzmann scheme. The macroscopic equation for this function is derived using multi-scale analysis. Numerical results are compared with theoretical and experimental ones for the problem of drop deformation under steady linear flows. A qualitative comparison with results given by a level contour reconstruction method for drop collision in three dimensions is also shown. Other numerical applications, such as flow past obstacles and a falling drop, are presented.
GENERATING CHAOTIC LIMIT CYCLES FOR A COMPLEX DUFFING–VAN DER POL SYSTEM USING A RANDOM PHASE
Authors: XU YONG , XU WEI , MAHMOUD GAMAL M.
Published: September 2005

Stochastic forces or random noises have been greatly used in studying the control of chaos of random real systems, but little is reported for random complex systems. Chaotic limit cycles of a complex Duffing–Van der Pol system with a random excitation is studied. Generating chaos via adjusting the intensity of random phase is investigated. We consider the positive top Lyapunov exponent as a criterion of chaos for random dynamical systems. It is computed based on the Khasminskii's formulation and the extension of Wedig's algorithm for linear stochastic systems. We demonstrate the stable behavior of deterministic system when noise intensity is zero by means of the top (local) Lyapunov exponent. Poincaré surface analysis and phase plot are used to confirm our results. Later, random noise is used to generate chaos by adjusting the noise intensity to make the top (local) Lyapunov exponent changes from a negative sign to a positive one, and the Poincaré surface analysis is also applied to verify the obtained results and excellent agreement between these results is found.
BOSONIC STRING THEORY IN BACKGROUND FIELDS BY CANONICAL METHODS
Authors: SAZDOVIĆ B.
Published: September 2005

We investigate classical dynamics of the bosonic string in the background metric, antisymmetric and dilaton fields. We use canonical methods to find Hamiltonian in terms of energy–momentum tensor components. The later are secondary constraints of the theory. Due to the presence of the dilaton field the Virasoro generators have nonlinear realization. We find that, in the curve space–time, opposite chirality currents do not commute. As a consequence of the two-dimensional general covariance, the energy–momentum tensor components satisfy two Virasoro algebras, even in the curve space–time. We emphasize that background antisymmetric and dilaton fields are the origin of space–time torsion and space–time nonmetricity, respectively.
BINARY SYSTEMS OF NEUTRAL MESONS IN QUANTUM FIELD THEORY
Authors: MACHET B. , NOVIKOV V. A. , VYSOTSKY M. I.
Published: September 2005

Quasidegenerate binary systems of neutral mesons of the kaon type are investigated in Quantum Field Theory (QFT). General constraints cast by analyticity and discrete symmetries P, C, CP, TCP on the propagator (and on its spectral function) are deduced. Its poles are the physical masses; this unambiguously defines the propagating eigenstates. It is diagonalized and its spectrum thoroughly investigated. The role of "spurious" states, of zero norm at the poles, is emphasized, in particular for unitarity and for the realization of TCP symmetry. The KL-KSmass splitting triggers a tiny difference between their CP violating parameters ∊Land ∊S, without any violation of TCP. A constant mass matrix like used in Quantum Mechanics (QM) can only be introduced in a linear approximation to the inverse propagator, which respects its analyticity and positivity properties; it is however unable to faithfully describe all features of neutral mesons as we determine them in QFT, nor to provide any sensible parametrization of eventual effects of TCP violation. The suitable way to diagonalize the propagator makes use of a bi-orthogonal basis; it is inequivalent to a bi-unitary transformation (unless the propagator is normal, which cannot occur here). Problems linked with the existence of different "in" and "out" eigenstates are smoothed out. We study phenomenological consequences of the differences between the QFT and QM treatments; the nonvanishing of the semileptonic asymmetry δS- δL, does not signal, unlike usually claimed, TCP violation, while ATCPkeeps vanishing when TCP is realized. We provide expressions invariant by the rephasing of K0and [Formula: see text].
A degree theory for compact perturbations of properC1 Fredholm mappings of index 0
Authors: Rabier Patrick J. , Salter Mary F.
Published: September 2005

We construct a degree for mappings of the form F + K between
Banach spaces, where F is C1
Fredholm of index
0
and K
is compact. This degree generalizes
both the Leray‐Schauder degree when F = I and the degree for
C1
Fredholm mappings of index 0
when K = 0. To exemplify
the use of this degree, we prove the “invariance‐of‐domain”
property when F + K
is one‐to‐one and a generalization of
Rabinowitz′s global bifurcation theorem for equations
F(λ, x) + K(λ, x) = 0.
Normal solvability of general linearelliptic problems
Authors: Volpert A. , Volpert V.
Published: September 2005

The paper is devoted to general elliptic problems in the
Douglis‐Nirenberg sense. We obtain a necessary and sufficient
condition of normal solvability in the case of unbounded domains.
Along with the ellipticity condition, proper ellipticity and
Lopatinsky condition that determine normal solvability of
elliptic problems in bounded domains, one more condition
formulated in terms of limiting problems should be imposed in the
case of unbounded domains.
The Cauchy problem and decay rates for strongsolutions of a Boussinesq system
Authors: González Francisco Guillén , da Rocha Márcio Santos , Medar Marko Rojas
Published: September 2005

The Boussinesq equations describe the motion of an incompressible
viscous fluid subject to convective heat transfer. Decay rates of
derivatives of solutions of the three‐dimension‐al Cauchy problem
for a Boussinesq system are studied in this work.
Correct selfadjoint and positive extensions ofnondensely defined minimal symmetric operators
Authors: Parassidis I. , Tsekrekos P.
Published: September 2005

Let A0
be a closed,
minimal symmetric operator from a Hilbert space ℍ

into
ℍ with domain not dense in ℍ. Let

also be a correct selfadjoint extension of A0.
The purpose of this paper is (1) to characterize, with the help of
, all the correct selfadjoint extensions B of
A0 with domain equal to , (2)
to give the solution of their corresponding problems, (3) to find
sufficient conditions for B
to be positive (definite) when
is positive (definite).
Internal stabilization of Maxwell′s equations inheterogeneous media
Authors: Nicaise Serge , Pignotti Cristina
Published: September 2005

We consider the internal stabilization of Maxwell′s equations
with Ohm′s law with space variable coefficients in a bounded
region with a smooth boundary. Our result is mainly based on an
observability estimate, obtained in some particular cases by the
multiplier method, a duality argument and a weakening of norm
argument, and arguments used in internal stabilization of scalar
wave equations.
Optimality conditions for systems driven by nonlinear evolution equations
Authors: Papageorgiou N.
Published: September 2005

Using the Dubovitskii‐Milyutin theory we derive necessary and sufficient conditions for optimality for a class of Lagrange optimal control problems monitored by a nonlinear evolution equation and involving initial and/or terminal constraints. An example of a parabolic control system is also included.
A nested decomposition algorithm for parallel computations of very large sparse systems
Authors: Šiljak D. D. , Zečević A. I.
Published: September 2005

In this paper we present a generalization of the balanced border block diagonal (BBD) decomposition algorithm, which was developed for the parallel computation of sparse systems of linear equations. The efficiency of the new procedure is substantially higher, and it extends the applicability of the BBD decomposition to extremely
large problems. Examples of the decomposition are provided for matrices as large as 250, 000 × 250, 000, and its performance is compared to other sparse decompositions. Applications to the parallel solution of sparse systems are discussed for a variety of engineering problems.
A unified approach to fixed‐order controller design via linear matrix inequalities
Authors: Iwasaki T. , Skelton R. E.
Published: September 2005

We consider the design of fixed‐order (or low‐order) linear controllers which meet certain performance and/or robustness specifications. The following three problems are considered; covariance control as a nominal performance problem,𝒬‐stabilization as a robust stabilization problem, and robust L∞ control problem as a robust performance problem. All three control problems are converted to a single linear algebra problem of solving a linear matrix inequality (LMI) of the type BGC + (BGC)T + Q < 0 for the unknown matrix G. Thus this paper addresses the fixed‐order controller design problem in a unified way. Necessary and sufficient conditions for the existence of a fixed‐order controller which satisfies the design specifications for each problem are derived, and an explicit controller formula is given. In any case, the resulting problem is shown to be a search for a (structured) positive definite matrix X such that X ∈ 𝒞1 and X−1 ∈ 𝒞2 where 𝒞1 and 𝒞2 are convex sets defined by LMIs. Computational aspects of the nonconvex LMI problem are discussed.
On adaptive control of mobile slotted aloha networks
Authors: Lim J.-T.
Published: September 2005

An adaptive control scheme for mobile slotted ALOHA is presented and the effect of capture on the adaptive control scheme is investigated. It is shown that with the proper choice of adaptation parameters the adaptive control scheme can be made independent of the effect of capture.
Mathematical theory of improvability for production systems
Authors: Jacobs David , Meerkov Semyon M.
Published: September 2005

A mathematical model for continuous improvement processes in production systems is formulated. Both constrained and unconstrained cases are addressed. A solution for the case of a serial production line with finite buffers and a Bernoulli model of machines reliability is given. In particular, it is shown that a production line is unimprovable under constraints if each buffer is on the average half full and each machine has equal probability of blockages and starvations. Based on this result, guidelines for continuous improvement processes are formulated.
Adaptive band‐limited disturbance rejection in linear discrete‐time systems
Authors: Ben-Amara Foued , Kabamba Pierre T. , Ulsoy A. Galip
Published: September 2005

The problem of adaptively rejecting a disturbance consisting of a linear combination of sinusoids with unknown and/or time varying frequencies for SISO LTI discrete‐time systems is considered. The rejection of the disturbance input is achieved by constructing the set of stabilizing controllers using the Youla parametrization and adjusting the Youla parameter to achieve asymptotic disturbance rejection. The first main result in this paper concerns off-line controller design where a controller that achieves regulation is numerically designed off‐line based on the assumption that only the sequence of discrete disturbance input values (as opposed to a model of the disturbance) is available. A least squares based optimization algorithm is used in the controller design. As expected, it is shown, under some mild assumptions, that if the off‐line designed controller achieves regulation, then it must include a model of the disturbance input. The second main result concerns on-line controller design where recursive versions of the off‐line algorithm used above for controller design are presented and their convergence properties analyzed. Conditions under which the on‐line algorithms yield an asymptotic controller that achieves regulation are presented. Conditions both for the case where the disturbance input properties are constant but unknown and for the case where they are unknown and time‐varying are given. The on‐line controller construction amounts to an adaptive implementation of the Internal Model Principle. The performance robustness of the off‐line designed controller in the face of plant model uncertainties is investigated. It is shown,
under some mild assumptions, that performance robustness is realized provided internal stability is maintained. The performance of the adaptation algorithms is illustrated through a simulation example.
Necessary conditions of optimality for infinite dimensional uncertain systems
Authors: Ahmed N. U. , Xiang X.
Published: September 2005

In this paper we consider optimal control problem for infinite dimensional uncertain systems. Necessary conditions of optimality are presented under the assumption that the principal operator is the infinitesimal generator of a strongly continuous semigroup of linear operators in a reflexive Banach space. Further, a computational algorithm suitable for computing the optimal policies is also given.
Global asymptotic stability of a passive juggling strategy: A possible parts‐feeding method
Authors: Swanson P. J. , Burridge R. R. , Koditschek D. E.
Published: September 2005

In this paper we demonstrate that a passive vibration strategy can bring a one‐degree‐of‐freedom ball to a specified periodic trajectory from all initial conditions. We draw motivation from the problem of parts feeding in sensorless assembly. We provide simulation results suggesting the relevance of our analysis to the parts
feeding problem.
Development of a finite‐element‐based design sensitivity analysis for buckling and postbuckling of composite plates
Authors: Guo Ruijiang , Chattopadhyay Aditi
Published: September 2005

A finite element based sensitivity analysis procedure is developed for buckling and postbuckling of composite plates. This procedure is based on the direct differentiation approach combined with the reference volume concept. Linear elastic material model and nonlinear geometric relations are used. The sensitivity analysis
technique results in a set of linear algebraic equations which are easy to solve. The procedure developed provides the sensitivity derivatives directly from the current load and responses by solving the set of linear equations. Numerical results are presented and are compared with those obtained using finite difference technique. The results show good agreement except at points near critical buckling load where discontinuities occur. The
procedure is very efficient computationally.
A modeling and control framework for operating large‐scale electric power systems under present and newly evolving competitive industry structures
Authors: Ilić Marija D. , Liu Xiaojun Shell
Published: September 2005

This paper introduces a systematic, structure‐based modeling framework for analysis and control of electric power systems for processes evolving over the mid‐term and long‐term time horizons. Much simpler models than the detailed dynamics specifically for control design at different hierarchical levels are obtained by applying both temporal and spatial separation. These simple models, or the aggregate models, represent the net effect of interactions among interconnected regions on specific hierarchical levels. They are exact, since no assumptions on weak interconnections among the subsystems are made. Moreover they are easily understood in terms of power flows among the regions. The approach is essential for improving present performance of the system. It is also potentially useful in a competitive utility environment in which it is critical to study the interplay between technical and economic processes.
Economic analysis of production bottlenecks
Authors: Lawrence Stephen R. , Buss Arnold H.
Published: September 2005

The management of bottlenecks has become a central topic in the planning and control of production systems. In this paper, we critically analyze bottlenecks from an economic perspective. Using a queueing network model, we demonstrate that bottlenecks are inevitable when there are differences in job arrival rates, processing rates,
or costs of productive resources. These differences naturally lead to the creation of bottlenecks both for facilities design and demand planning problems. To evaluate bottlenecks from an economic perspective, we develop the notion of an “economic bottleneck,” which defines resources as bottlenecks based on economic, rather than
physical, characteristics.
Effect of maternal age on the frequency of cytogenetic abnormalities in human oocytes
Authors: Pellestor F. , Anahory T. , Hamamah S.
Published: September 2005

The cytogenetic investigation of human oocytes was initiated in the Sixties, and for the last four decades, this field of research has never stopped progressing as new technologies appear. Numerous karyotyping studies and molecular cytogenetic studies have been reported to date, providing a large body of data on the incidence and the distribution of chromosomal abnormalities in human female gametes, but also displaying a great variability in results, which may be essentially attributable to the technical limitations of these in situ methods when applied to human oocytes. Essentially, the most relevant analyses have led to the estimate that 15–20% of human oocytes display chromosome abnormalities, and they have emphasized the implication of both whole chromosome nondisjunction and chromatid separation in the occurrence of aneuploidy in human oocytes. The effect of advanced maternal age on the incidence of aneuploidies has also been investigated in human oocytes. Most previous studies have failed to confirm any relationship between maternal age and aneuploidy frequency in human oocytes, whereas the more recent reports based on large samples of oocytes or polar bodies have provided evidence for a direct correlation between increased aneuploidy frequency and advanced maternal age, and have clarified the contribution of the various types of malsegregation in the maternal age-dependent aneuploidies.
Effect of paternal age on the frequency of cytogenetic abnormalities in human spermatozoa
Authors: Buwe A. , Guttenbach M. , Schmid M.
Published: September 2005

Many surveys have been performed to find etiological relationships between pregnancy outcome and specific risk factors, such as exposure to chemicals and radiation or parental age. Advanced maternal age is a strong risk factor for trisomic pregnancies, albeit there are considerable variations among the different chromosomes. The definite incidence of the various structural and numerical chromosome aberrations in spontaneous abortions and liveborns is well known, as well as the rate of maternally and paternally derived rearrangements. Nevertheless studies have failed to assert an age-dependent risk for men fathering chromosomally abnormal children. New techniques using fluorescence in situ hybridization render it possible to analyze spermatozoa directly for numerical and, to some extent, for structural aberrations. This article compiles the findings of studies on human spermatozoa over the last few years.
Individual variation in the frequency of sperm aneuploidy in humans
Authors: Rubes J. , Vozdova M. , Oracova E. , Perreault S.D.
Published: September 2005

To examine interindividual differences in sperm chromosome aneuploidy, repeated semen specimens were obtained from a group of ten healthy men, aged 20–21 at the start of the study, and analyzed by multi-color fluorescence in situ hybridization (FISH) analysis to determine the frequencies of sperm aneuploidy for chromosomes X, Y, 8, 18 and 21 and of diploidy. Semen samples were obtained three times over a five-year period. Statistical analysis examining the stability of sperm aneuploidy over time by type and chromosome identified two men who consistently exhibited elevated frequencies of sperm aneuploidy (stable variants): one with elevated disomy 18 and one with elevated MII diploidy. Differences among frequencies of aneuploidy by chromosome were also seen. Overall, disomy frequencies were lower for chromosome X, 8 and 18 than for chromosomes 21 or Y and for XY aneuploidy. The frequency of chromosome Y disomy did not differ from XY sperm frequency. Also, the frequency of meiosis I (XY) and II (YY + XX) sex chromosome errors did not differ in haploid sperm, but the frequency of MII errors was lower than MI errors in diploid sperm. Frequencies of sperm aneuploidy were similar between the first sampling period and the second, two years later. However, the frequency of some types of aneuploidy (XY, disomy Y, disomy 8, total autosomal disomies, total diploidy, and subcategories of diploidy) increased significantly between the first sampling period and the last, five years later, while others remained unchanged (disomy X, 21 and 18). These findings confirm inter-chromosome differences in the frequencies of disomy and suggest that some apparently healthy men exhibit consistently elevated frequencies of specific sperm aneuplodies. Furthermore, time/age-related changes in sperm aneuploidy may be detected over as short a period as five years in a repeated-measures study.
Meiotic spindle checkpoints for assessment of aneuploid oocytes
Authors: Steuerwald N.
Published: September 2005

The spindle assembly checkpoint suspends cell cycle progression if improperly aligned chromosomes are detected at metaphase. Evolutionarily conserved kinetochore-associated proteins are believed to be key elements of this regulatory pathway. A breakdown in checkpoint function could bring about genomic instability, which may be responsible for the prevalence of aneuploidy in oocytes of older women. Maternal aging remains the overwhelming factor in the etiology of human aneuploidy in assisted reproduction. Defects in cell cycle checkpoint genes may play a role in its development. The existence of such monitoring mechanisms in oocytes has long been controversial. Studies providing evidence in support of and against their existence are reviewed.
Segregation of chromosomes in sperm of Robertsonian translocation carriers
Authors: Roux C. , Tripogney C. , Morel F. , Joanne C. , Fellmann F. , Clavequin M.C. , Bresson J.L.
Published: September 2005

Robertsonian translocations are the most frequent structural chromosomal abnormalities in humans and can affect fertility, with various degrees of sperm alterations in men; or the pregnancy outcome of the carriers. The studies on meiotic segregation of chromosomes in sperm of Robertsonian translocation males find a majority of normal or balanced spermatozoa for the chromosomes related to the translocation (mean 85.42%; range 60–96.60%). Furthermore, recent studies suggest an interchromosomal effect. Studies on spermatozoa from translocation carriers, and in mouse models help the comprehension of the meiotic segregation mechanisms. Results of meiotic segregation analysis in man could be integrated in genetic counselling especially when assisted reproductive technology is required.