bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological and molecular evidence of natural interspecific hybridization in the diploid potatoSolanum kurtzianumfrom Argentina
Authors: Bedonni María Cecilia , Camadro Elsa Lucila
Published: January 2009

The common potato, Solanum tuberosum L. subsp. tuberosum , is a tetrasomic tetraploid. This subspecies has approximately 220 related tuber-bearing species that constitute a genetic pool of enormous breeding value. The diploid species Solanum kurtzianum Bitter et Wittm., described as resistant to drought and nematodes, grows in northwestern and western Argentina and can naturally hybridize with the related diploids Solanum chacoense Bitter, Solanum spegazzinii Bitter, and Solanum maglia Schltdl., in areas of sympatry. In this species, the variability for morphological phenotypes and pollen–pistil relations in intra- and interspecific crosses is large. To investigate whether S. kurtzianum accessions available at the Germplasm Bank in Argentina belong to one taxon with great morphological plasticity or are hybrid and (or) segregant populations, these and accessions of the other three species were characterized using morphological and molecular (SSR) markers. Data were statistically analyzed with ANOVAs and AMOVA. With univariate ANOVA, only 11 characters out of 33 evaluated were statistically significant among species. With multivariate analyses, the grouping did not reflect a priori taxonomic assignments; when population averages were used, a tendency was observed towards grouping by geographical origin. With the AMOVA, only individuals within accessions were separated. Interspecific hybridization and introgression in areas of sympatry can explain these results.
A multivariate morphometric analysis of Solidago subsect. Glomeruliflorae (Asteraceae: Astereae)
Authors: Cook Rachel E. , Semple John C. , Baum Bernard R.
Published: January 2009

A multivariate morphometric study of Solidago subsection Glomeruliflorae (Torr. & A. Gray) Nesom was undertaken on a matrix of 45 characters by 368 plants to assess the morphological differences among the members of the complex and to determine their appropriate taxonomic ranks. The numbers of a priori groups tested were based on taxa recognized in floristic literature, examination of type specimens and 3214 herbarium specimens, and observations of plants in the field and greenhouse. Analyses were performed to determine statistical support for eight a priori species level groups: Solidago albopilosa E.L. Braun, Solidago caesia  L., Solidago curtisii Torr. & A. Gray, Solidago flexicaulis L., Solidago glomerata Michx., Solidago lancifolia (Torr. & A. Gray) Chapm., Solidago macrophylla  Pursh, and Solidago ouachitensis C.E.S Taylor & R.J. Taylor. Additional analyses were preformed to determine statistical support for varietal level a priori groups within S. caesia and S. curtisii. Statistical support for recognizing all 10 a priori groups varied, although in all analyses, the P values were always well below α of 0.05. Based on the results of the discriminant analyses, the following taxa are recognized: S. albopilosa, S. caesia var. caesia , S. caesia var. zedia , S. curtisii var. curtisii , S. curtisii var. flaccidifolia , S. flexicaulis, S. glomerata, S. lancifolia, S. macrophylla, and S. ouachitensis.
Factors affecting pine pitch canker modelled on Michaelis–Menten kineticsThis article is one of a collection of papers based on a presentation from theStem and Shoot Fungal Pathogens and Parasitic Plants: the Values of Biological Diversitysession of the XXII International Union of Forestry Research Organization World Congress meeting held in Brisbane, Queensland, Australia, in 2005.
Authors: Hammerbacher A. , Wright L. P. , Wingfield B. D. , Wingfield M. J. , Coutinho T. A.
Published: January 2009

Fusarium circinatum Nirenberg and O’Donnell is an important pathogen of pine seedlings and cuttings in South Africa. The fungus causes plant death in nurseries, as well as during establishment of pine plantations. The aim of this study was to consider the effects of wound type, spore concentration, and environmental stress on infection incidence. Pine seedlings were inoculated using three wounding methods and five spore concentrations. Inoculated seedlings were incubated under optimal environmental conditions, suboptimal conditions, and suboptimal conditions combined with a fungicide treatment. Results showed that the mean percentage infection caused by increasing spore concentrations can be described by the Michaelis–Menten function. The gradient of the function, as well as the asymptotic maximum level of infection, was dependant on environmental stress and the physiological state of the host, as well as the wounding method. Spore concentration had the highest influence on infection incidence in physiologically stressed seedlings. Fungicide treatment did not influence the rate of infection incidence in comparison with the treatments conducted under optimal environmental conditions, but significantly lowered the asymptotic maximum level of infection incidence. Seedlings wounded on the stems had the highest infection incidence, when compared with other wounding methods.
Fish antifreeze proteins: physiology and evolutionary biology
Authors: Davies Peter L. , Hew Choy L. , Fletcher Garth L.
Published: January 2009

Many marine teleosts have adapted to ice-laden seawater by evolving antifreeze proteins and glycoproteins. These proteins are synthesized in the liver for export to the blood where they circulate at levels of up to 20 mg/mL. There are at least four distinct antifreeze protein classes differing in carbohydrate content, amino acid composition, protein sequence, and secondary structure. In addition to antifreeze structural diversity, fish species differ considerably with respect to mechanisms controlling seasonal regulation of plasma antifreeze concentrations. Some species synthesize antifreeze proteins immediately before the onset of freezing conditions, some synthesize them in response to such conditions, whereas others possess high concentrations all year. Endogenous rhythms, water temperature, photoperiod, and pituitary hormones have all been implicated as regulators of plasma antifreeze protein levels. The structural diversity of antifreeze proteins and their occurrence in a wide range of fish species suggest that they evolved separately and recently during Cenozoic glaciation. Invariably, the genes coding for these antifreeze proteins are amplified, sometimes as long tandem arrays, suggesting intense selective pressure to produce large amounts of protein. The distribution of antifreeze gene types among fish species suggests that they could serve as important tools for studying phylogenetic relationships.
Opioid involvement in parasite-induced behavioural modifications: evidence from hamsters infected with Schistosoma mansoni
Authors: Kavaliers Martin , Podesta Ron
Published: January 2009

Although it is well established that parasites can modify the behaviour of their hosts, relatively little is known about the neurochemical correlates of such effects. In the present study we examined the relationships between parasite infection, endogenous opioid system, and host behaviour. Male golden hamsters (Mesocricetus auratus) infected with the blood fluke Schistosoma mansoni for 25 days (prepatent) displayed a significant enhancement of their locomotory activity levels, whereas patent animals infected for 40 days displayed a significant decrease in their activity. The schistosome-induced increase in activity was blocked by peripheral administration of the specific antagonist toward δ-opiate receptors, ICI 154,129, while the decrease in activity was blocked by the prototypic μ-opiate antagonist naloxone. In a parallel manner, the δ antagonist blocked the increased locomotor activity induced by a low dose (5.0 mg/kg) of the prototypic opiate agonist morphine, while the μ antagonist blocked the reduction in activity induced by a higher dose (10 mg/kg) of morphine. These observations, along with previously described opioid-mediated analgesic responses in parasitized hamsters, suggest that schistosome infection can lead to a differential augmentation of endogenous opioid activity. These findings suggest that parasite-induced modifications of host behaviour may, in part, arise from alterations in opioid modulation of behaviour.
Morphological variation and taxonomy of chromosomally differentiated Peromyscus from the Pacific Northwest
Authors: Allard Marc W. , Greenbaum Ira F.
Published: January 2009

Analysis of 28 morphological characters supports the existence of two karyotypically defined species of Peromyscus on Vancouver Island and islands in the Queen Charlotte Strait and the Strait of Georgia. Morphology of insular and mainland populations from Washington and British Columbia is congruent with karyotypic data indicating that only the smaller, low fundamental number deer mice should be retained with Peromyscus maniculatus, and that the larger, high fundamental number forms should be referred to Peromyscus areas. Accordingly, P. maniculatus ranges throughout Vancouver Island, is the only deer mouse inhabiting the islands of the Strait of Georgia, and occurs on some of the more northern small islands. Insular forms of P. areas occur on northern and western Vancouver Island and on the islands in the Queen Charlotte Strait. The existence of two species in this geographic area indicates the need for a revision of the subspecific taxonomy. From the patterns of morphological variation among the examined populations of karyotypically characterized individuals, we offer hypotheses that should be tested in the development of formal intraspecific taxonomic decisions.
Genetic and phenotypic population structure of the Coenonympha tullia complex (Lepidoptera: Nymphalidae: Satyrinae) in California: no evidence for species boundaries
Authors: Porter Adam H. , Geiger Hansjürg
Published: January 2009

Decisions regarding species status of taxa showing geographic replacement are explicit hypotheses about population structure. The structure of 21 populations of the Coenonympha tullia group from northern California, southwestern Oregon, and northern Nevada was analyzed for evidence of reproductive isolation. These samples included five subspecies (california, eryngii, ampelos, eunomia, and mono) nominally placed in three species (california, ampelos, and ochracea). We found very high intra- and inter-population variability in the "diagnostic" wing pattern characters used by previous authors. There is evidence of intergradation between eryngii and eunomia in southwestern Oregon, and between california and ampelos in the eastern Feather River drainage in California. A complex cline involving California, eryngii, and ampelos occurs in the Pit River drainage of northeastern California. The taxon mono appears distinct, apparently because of an absence of Coenonympha populations in the expected mono–ampelos contact area. Electrophoretic analysis of the same 21 populations showed very high intrapopulation genetic variability (expected heterozygosity = 13.5–20.4%, percentage of polymorphic loci (most common allele < 99%) = 35.5–58.8%; 14 alleles at the locus for phosphoglucose isomerase (one population with 11 alleles)). However, interpopulation (geographic) variability was extremely low. Standardized genetic variance among populations (FST, using Wright's formulation) in contact zones indicates that gene flow is probably uninterrupted between the subspecies california, eryngii, ampelos, and eunomia. FST values for the isocitrate dehydrogenase locus indicate that present-day gene flow is probably unimportant in maintaining similarity between ampelos and mono. The genetic population structure is reminiscent of highly vagile colonizing species, but this may be largely historical, due to post-Pleistocene range changes rather than high present-day interpopulation migration rates. We conclude that all California populations are conspecific. Only the subspecies mono is clearly separated from the others, at the level 0.034 (Nei's unbiased distance), approximating that of weak subspecies in other taxa. The North American entities should all be provisionally classified as subspecies of the holarctic species tullia unless evidence is found to support their separation.
The comparative epizootiology of Capillaria hepatica (Nematoda) in urban rodents from different habitats of Baltimore, Maryland
Authors: Childs J. E. , Glass G. E. , Korch Jr. G. W.
Published: January 2009

The prevalence and intensity of Capillaria hepatica infections in four rodent species (Rattus norvegicus, Mus musculus, Microtus pennsylvanicus, and Peromyscus leucopus) trapped from sites in different habitats of Baltimore were examined from 1980 to 1986. Norway rats were frequently infected (87.4%), house mice rarely infected (5.4%), and no lesions were observed in meadow voles or white-footed mice. Rats from residential locations had significantly higher prevalence and intensity of infection compared with rats from parkland locations, findings not related to differences in the age structure of the populations. Prevalence and severity of lesions were positively associated with increasing body mass in rats and mice. No sex-related differences were found. Infection rates were positively correlated with relative densities of rat and mouse populations; results were corroborated by interviews conducted with 87 household residents.
The effects of oil contamination and cleaning on sea otters (Enhydra lutris). II. Metabolism, thermoregulation, and behavior
Authors: Davis R. W. , Williams T. M. , Thomas J. A. , Kastelein R. A. , Cornell L. H.
Published: January 2009

The purpose of this study was to develop a method to clean and rehabilitate sea otters (Enhydra lutris) that might become contaminated during an oil spill and to determine which physiological and behavioral factors were important in restoring the insulation provided by the fur. Tests were conducted on 12 sea otters captured in Alaska and brought to the Sea World Research Institute in San Diego. Measurements of average metabolic rate, core body temperature, behavior, and squalene (the major lipid of sebum) concentration on the fur were made under three conditions: (i) before oiling (base line), (ii) 1–3 days after 20% of the body surface area was covered with fresh crude oil, and (iii) after cleaning. Under base-line conditions in water at 13 °C, average metabolic rate was 8.0 W/kg, core body temperature was 38.9 °C, and whole body thermal conductance was 10.7 W/(m2∙ °C). Otters spent 35% of their time grooming, 45% resting, 10% swimming, and 10% feeding. The squalene concentration on the fur averaged 3.7 mg/g fur. Oiling increased thermal conductance 1.8 times. To compensate for the loss of insulation and maintain a normal core body temperature (39 °C), the otters increased average metabolic rate (1.9 times) through voluntary activity and shivering; the time spent grooming and swimming increased 1.7 times. Using Dawn detergent, we were able to clean the oiled fur during 40 min of washing and rinsing. Grooming activity by the otters was essential for restoring the water-repellent quality of the fur. Core body temperature, average metabolic rate, and thermal conductance returned to base-line levels 3–6 days after cleaning. Squalene was removed by cleaning and did not return to normal levels in the oiled area after 7 days. Veterinary care was important to keep the otters healthy. At least 1–2 weeks should be allowed for otters to restore the insulation of their fur and for recovery from the stress of oiling and cleaning.
A phylogenetic reassessment of the monophyletic status of the family Soleidae, with comments on the suborder Soleoidei (Pisces; Pleuronectiformes)
Authors: Chapleau François , Keast Allen
Published: January 2009

This article presents the phylogenetic conclusions of an osteological study of species belonging to the subfamilies (Soleinae and Achirinae) of the dextral flatfish family Soleidae (Pieuronectiformes; Soleoidei). A cladistic analysis of the data revealed that the subfamilies, but not the family, are monophyletic. The Soleinae were found to be more closely related to the other soleoid family, the Cynoglossidae, than to the Achirinae. If we accept the principle that only monophyletic groups are to be admitted into Linnean classification, it is suggested that the two subfamilies be raised to the family level. The anatomical data led to the proposal (with caution) that the sister group of the achirid–soleid–cynoglossid lineage is the pleuronectid subfamily Samarinae. Consequently, it is suggested that the suborder Soleoidei be eliminated by incorporating its three families into the Pleuronectoidei which becomes monophyletic. Also, it is proposed that the Pleuronectid subfamilies (Pleuronectinae, Poecilopsettinae, Paralichthodinae, Rhombosoleinae, Samarinae) be raised to the family level. However, since the monophyletic status of these taxa is dubious (except for the Samarinae) any hypothesis including them must await a proper cladistic analysis of their intra- and inter-relationships.
Évaluation de la méthode de détermination de l'âge en fonction de la masse du cristallin chez le bouquetin (Capra pyrenaica Schinz, 1838)
Authors: Vigal Carlos R. , Machordom Annie
Published: January 2009

The relationship between lens mass and age determined in 80 wild goats (Capra pyrenaica Schinz, 1838) from Sierra de Gredos (Avila), follows the equation Y = 79.36 + 259.94 log X, where Y is lens mass (mg) and X wild goat age (months). Lens masses of males and females do not differ significantly. Age-class (1-year classes) cannot be determined with 95% confidence from lens mass in animals 2 years and older. This method of age determination can be useful in cases where the age of young animals cannot be evaluated with accuracy otherwise; age determination by observation of teeth eruption or counting of growth rings of the horns is generally very valuable.
The role of intruder behaviour in nestmate recognition by bumble bees (Hymenoptera: Apidae)
Authors: Plowright R. C. , Fuller G. A.
Published: January 2009

A series of experiments on the response of bumble bees to the introduction of bees into their colonies are reported. The two main effects, both of which were statistically significant, were (i) class of intruder (nestmate, alien conspecific, or heterospecific) and (ii) whether or not the intruder was anaesthetized. Significant interactions were also obtained: the difference in response of the resident bees to whether the intruders were conspecific or heterospecific depended also on whether or not the intruders were anaesthetized. The relevance of these results to the possibility that intruders are recognized by their behaviour (as well as their odour) is discussed.
A note on parasitism of the phytonematodes Meloidogyne sp. and Heterodera fici by Pasteuria penetrans
Authors: de O. Abrantes Isabel M. , Vovlas Nicola
Published: January 2009

The endoparasite of several phytonematodes, Pasteuria penetrans, was found to parasitize juveniles and males of a Meloidogyne sp. in Portugal and juveniles of Heterodera fici in Italy. The infectivity on Meloidogyne males and H. fici juveniles is illustrated with light, scanning, and transmission electron microscopy. The great number of spores found attached on both genera characterizes these nematodes as potential hosts, and establishes a new host and distribution record for this antagonist of plant-parasitic nematodes.
LEPTON FLAVOR VIOLATING li→ljγγ DECAYS INDUCED BY SCALAR UNPARTICLE
Authors: ILTAN E. O.
Published: January 2009

We study the radiative lepton flavor violating li→ljγγ decays in the case that the lepton flavor violation is induced by the scalar unparticle mediation. We restrict the scaling dimension du and the scalar unparticle–photon–photon coupling by using the experimental upper limit of the branching ratio of the decay μ→eγγ. Furthermore, we predict the BRs of the other radiative decays by using the restrictions we get. We observe that the measurements of upper limits of BRs of these decays ensure considerable information for testing the possible signals coming from unparticle physics.
CAN WE EXTRACT THE PION ELECTROMAGNETIC FORM FACTOR FROM A t-CHANNEL DIAGRAM ONLY?
Authors: MART T.
Published: January 2009

We show that we are able to extract the pion electromagnetic form factor by using the recent charged pion electroproduction data from JLab and a simple t-channel diagram. For this purpose we have performed the Q2-independent and dependent analyses. The result of the first analysis is in good agreement with those of previous works and fit the Maris and Tandy model as well as the monopole parametrization which describes a pion radius of 0.672 fm. The result of the second analysis corroborates the findings in the first analysis. Our findings therefore provide a direct proof that at the given kinematics the t-channel diagram really dominates the process. This could also set a new constraint to the phenomenological models that try to describe the process.
TWO-LOOP VACUUM DIAGRAMS IN BACKGROUND FIELD AND THE HEISENBERG–EULER EFFECTIVE ACTION
Authors: KRASŇANSKÝ MAREK
Published: January 2009

We show that in arbitrary even dimensions, the two-loop scalar QED Heisenberg–Euler effective action can be reduced to simple one-loop quantities, using just algebraic manipulations, when the constant background field satisfies F2 = -f2𝟙, which in four dimensions coincides with the condition for self-duality, or definite helicity. This result relies on new recursion relations between two-loop and one-loop diagrams, with background field propagators. It also yields an explicit form of the renormalized two-loop effective action in a general constant background field in two dimensions.
B PHYSICS AT LHCb
Authors: ALTARELLI MONICA PEPE , TEUBERT FREDERIC
Published: January 2009

LHCb is a dedicated detector for b physics at the LHC (Large Hadron Collider). In this paper we present a concise review of the detector design and performance together with the main physics goals and their relevance for a precise test of the Standard Model and search of New Physics beyond it.
MULTISCROLL IN COUPLED DOUBLE SCROLL TYPE OSCILLATORS
Authors: DANA SYAMAL KUMAR , SINGH BRAJENDRA K. , CHAKRABORTY SATYABRATA , YADAV RAM CHANDRA , KURTHS JÜRGEN , OSIPOV GREGORY V. , ROY PRODYOT KUMAR , HU CHIN-KUN
Published: January 2009

A unidirectional coupling scheme is investigated in double scroll type chaotic oscillators that reveal interesting multiscroll dynamics. Instead of using self-oscillatory systems, in this scheme, double scroll chaos from one oscillator is forced into another similar oscillator in a resting state. This coupling scheme is explored in the Chua oscillator, a modified Chua oscillator and the Lorenz oscillator. We have modified the Chua oscillator by simply changing its piecewise linear function slightly, thereby deriving a new 3-scroll attractor. We have observed 4-scroll, 6-scroll attractors in the driven Chua oscillator and the modified Chua oscillator respectively in an intermittency regime of weaker coupling. We have extended the coupling scheme to the Lorenz system when even more interesting multiscroll dynamics (3-, 4-, 5-, 6-scroll) is observed with decreasing coupling strength. It appears as if a hidden multiscroll structure unfolds with weakening coupling interactions. One after another, additional scrolls appear in the driven Lorenz system when the coupling strength is gradually decreased in the weaker coupling regime. The origin of such multiscroll dynamics is explained using eigenvalue analysis and a bifurcation diagram. A schematic diagram of the multiscroll trajectories is presented to further elucidate the evolution of the scrolls. Experimental evidence is also presented using the Chua circuit and an electronic analog of the Lorenz system.
CHAOTIC DYNAMICS OF A NONLINEAR ELECTRONIC CONVERTER
Authors: CAMPOS-CANTÓN E. , MURGUÍA J. S. , ROSU H. C.
Published: January 2009

The nonlinear electronic converter used by Rulkov and collaborators [Rulkov et al., 2001], which is the core of their chaotic oscillator, is modeled and simulated numerically by means of an appropriate direct relationship between the experimental values of the electronic components of the system and the mathematical model. This relationship allows us to analyze the chaotic behavior of the model in terms of a particular bifurcation parameter k. Varying the parameter k, quantitative results of the dynamics of the numerical system are presented, which are found to be in good agreement with the experimental measurements that we performed as well. Moreover, we show that this nonlinear converter belongs to a class of 3-D systems that can be mapped to the unfolded Chua's circuit. We also report a wavelet transform analysis of the experimental and numerical chaotic time series data of this chaotic system. The wavelet analysis provides us with information on such systems in terms of the concentration of energy which is the standard electromagnetic interpretation of the L2 norm of a given signal.
SADDLE-TYPE TORUS BRAIDS IN QUASIPERIODICALLY DRIVEN SYSTEMS: CROSSOVER MAPS OF TRANSVERSALLY INTERSECTING MANIFOLDS
Authors: ZIBRAT ZACHARY H. , SZERI ANDREW J.
Published: January 2009

In [Spears et al., 2005] it was demonstrated that insight into the geometry and topology of attractors for nonlinear oscillators driven by n incommensurate frequencies may be obtained from the study of n Poincaré maps defined on global cross-sections. The attractors take the form of stable torus braids. Here, attention is focused on saddle-type torus braids in similar systems. Transverse intersections of stable and unstable manifolds are computed using the phase slice method, along with the application of the crossover map. This neatly maps from one global Poincaré section to another. As such, it can be used to compute lobe intersection geometries in the remaining n - 1 Poincaré sections after doing so by the phase slice method in the first.
LIMIT CYCLE BIFURCATIONS IN NEAR-HAMILTONIAN SYSTEMS BY PERTURBING A NILPOTENT CENTER
Authors: HAN MAOAN , JIANG JIAO , ZHU HUAIPING
Published: January 2009

As we know, Hopf bifurcation is an important part of bifurcation theory of dynamical systems. Almost all known works are concerned with the bifurcation and number of limit cycles near a nondegenerate focus or center. In the present paper, we study a general near-Hamiltonian system on the plane whose unperturbed system has a nilpotent center. We obtain an expansion for the first order Melnikov function near the center together with a computing method for the first coefficients. Using these coefficients, we obtain a new bifurcation theorem concerning the limit cycle bifurcation near the nilpotent center. An interesting application example & a cubic system having five limit cycles & is also presented.
STABILITY AND HOPF BIFURCATION OF A DELAYED NETWORK OF FOUR NEURONS WITH A SHORT-CUT CONNECTION
Authors: MAO XIAOCHEN , HU HAIYAN
Published: January 2009

This paper reveals the dynamics of a delayed neural network of four neurons, with a short-cut connection through a theoretical analysis and some case studies of both numerical simulations and experiments. It presents a detailed analysis of the stability and the stability switches of the network equilibrium, as well as the Hopf bifurcation and the bifurcating periodic responses on the basis of the normal form and the center manifold reduction. Afterwards, the study focuses on the validation of theoretical results through numerical simulations and circuit experiments. The numerical simulations and the circuit experiments not only show good agreement with theoretical results, but also show abundant effects of the short-cut connection on the network dynamics.
A REPRESENTATIVE DISCRETE-TIME MODEL FOR UNCOVERING SLOW AND FAST SCALE INSTABILITIES IN BOOST POWER FACTOR CORRECTION AC-DC PRE-REGULATORS
Authors: EL AROUDI ABDELALI , ORABI MOHAMED , MARTINEZ-SALAMERO LUIS
Published: January 2009

Boost Power Factor Correction (PFC) AC-DC converter under fixed frequency average current control is a nonlinear and nonautonomous dynamical system characterized by two different forcing periods and thus by two different scales of time. Four different kinds of standard instability phenomena are possible for this system, depending on the parameters of the circuit. A combination of more than one instability phenomenon can also take place. In this paper, we carry out a careful and an accurate modeling of the system. First, we put into evidence most of the nonlinear behaviors that could occur in the system by using the switched circuit-based model and then we derive a unified representative discrete-time model that is able to predict accurately all these behaviors.
IMPLEMENTATION OF COGNITIVE CONTROL FOR A HUMANOID ROBOT
Authors: KAWAMURA KAZUHIKO , GORDON STEPHEN M. , RATANASWASD PALIS , ERDEMIR ERDEM , HALL JOSEPH F.
Published: January 2009

Engineers have long employed control systems utilizing models and feedback loops to control real-world systems. Limitations of model-based control led to a generation of intelligent control techniques such as adaptive and fuzzy control. The human brain, on the other hand, is known to process a variety of inputs in parallel, and shift between different levels of cognitive activities while ignoring distractions to focus on the task in hand. This process, known as cognitive control in psychology, is unique to humans and a handful of animals. We are interested in implementing such cognitive control functionalities for our humanoid robot ISAC. This paper outlines the features of multiagent-based cognitive architecture for a humanoid robot and the progress made toward the realization of cognitive control functionalities using attention, working memory and internal rehearsal. Several experiments have been conducted to show that the implementation of an integrated cognitive robot architecture is feasible.
ZMP COMPLIANT GAIT GENERATION STRATEGIES FOR SEVEN-MASS BIPED ROBOTS
Authors: KANNIAH JAGANNATHAN , LWIN ZAR NI
Published: January 2009

This paper presents a simple computational technique to generate ZMP compliant gait trajectories for seven-mass biped robots with no torso. The generation of such ZMP compliant trajectories for one- and three-mass approximations of biped robots have been developed earlier and presented elsewhere. In a one-mass case, the hip is assumed to move according to a self-compensating pattern. In a three-mass case, the swinging foot has been made to perform the prescribed motion and rest of the body is used as the compensating motion. In this work, it is reasoned that such simple techniques are not applicable for seven-mass representation, due to the complexity of the structure. One needs to make realistic approximations without losing model relevance. It is suggested that by sensibly ganging the motion of primitive limb elements, an effective solution can be facilitated. With simple iterative computations, ZMP compliant body trajectories are obtained. Patterns generated by this method agree with earlier solutions obtained by others.
HUMAN VERSUS HUMANOID ROBOT BIODYNAMICS
Authors: IVANCEVIC VLADIMIR G. , IVANCEVIC TIJANA T.
Published: January 2009

In this paper we compare and contrast modern dynamical methodologies common to both humanoid robotics and human biomechanics. While the humanoid robot's motion is defined on the system of constrained rotational Lie groups SO(3) acting in all major robot joints, human motion is defined on the corresponding system of constrained Euclidean groups SE(3) of the full (rotational + translational) rigid motions acting in all synovial human joints. In both cases the smooth configuration manifolds, Q rob and Q hum , respectively, can be constructed. The autonomous Lagrangian dynamics are developed on the corresponding tangent bundles, TQ rob and TQ hum , respectively, which are themselves smooth Riemannian manifolds. Similarly, the autonomous Hamiltonian dynamics are developed on the corresponding cotangent bundles, T*Q rob and T*Q hum , respectively, which are themselves smooth symplectic manifolds. In this way a full rotational + translational biodynamics simulator has been created with 270 DOFs in total, called the Human Biodynamics Engine, which is currently in its validation stage. Finally, in both the human and the humanoid case, the time-dependent biodynamics generalizing the autonomous Lagrangian (of Hamiltonian) dynamics is naturally formulated in terms of jet manifolds.
BIOLOGICAL PRINCIPLES OF CONTROL SELECTION FOR A HUMANOID ROBOT'S DYNAMIC BALANCE PRESERVATION
Authors: VUKOBRATOVIĆ MIOMIR , HERR HUGH M. , BOROVAC BRANISLAV , RAKOVIĆ MIRKO , POPOVIC MARKO , HOFMANN ANDREAS , JOVANOVIĆ MILOŠ , POTKONJAK VELJKO
Published: January 2009

This paper presents a contribution to the study of control law structures and to the selection of relevant sensory information for humanoid robots in situations where dynamic balance is jeopardized. In the example considered, the system first experiences a large disturbance, and then by an appropriate control action resumes a "normal" posture of standing on one leg. In order to examine the control laws used by humans, an experiment was performed in which a human subject was subjected to perturbations and the ensuing reactions were recorded to obtain complete information about the subject's motion and ground reaction force. Then, a humanoid model was advanced with characteristics matching those of the experimental human subject. The whole experiment was simulated so as to achieve a simulated motion that was similar to that of the human test subject. The analysis of the control laws applied, and the behavior of selected ground reference points (ZMP, CMP and CM projection on the ground surface), provided valuable insight into balance strategies that humanoid robots might employ to better mimic the kinetics and kinematics of humans compensating for balance disturbances.
The dream of a global knowledge network—A new approach
Authors: Doerr Martin , Iorizzo Dolores
Published: January 2009

Decades of research have been devoted to the goal of creating systems which integrate information into a global knowledge network, yet we still face problems of cross-repository interoperability, lack of public infrastructure, and a coherent research agenda—both theoretical and practical—to face these challenges. Interest in the semantic Web has revived the dream, but many are sceptical. This article offers a breakthrough to problems of semantic interoperability and defends the feasibility of a global knowledge network against traditional counterarguments. It offers a new approach based on (i) interdisciplinary research of scholarly and scientific discourse, (ii) a generic global ontological model based on relations and co-reference rather than objects, (iii) semi-automatic maintenance of co-reference links, and (iv) public engagement in the creation and development of the network.
Accessible Computing -- Past Trends and Future Suggestions
Authors: Newell Alan F.
Published: January 2009

This article gives a personal perspective on Glinert and York's 1992 paper, focusing on whether and how the situation has changed over the past 15 years, and makes recommendations for the future of the field of accessible computing with a particular focus on the needs of older people and people with cognitive dysfunction.
Calendar
Authors: Stanik John
Published: January 2009

Macworld Conference and Expo
Public Health Certification
Authors: Gebbie Kristine M.
Published: January 2009

In 2003, the Institute of Medicine (IOM) recommended voluntary certification of graduates achieving the Master of Public Health degree. The Association of Schools of Public Health (ASPH), the American Public Health Association, the Association of State and Territorial Health Officials, the National Association of County and City Health Officials, and the Association for Prevention Teaching and Research joined together to establish the National Board of Public Health Examiners ( 5 ). This new body will certify graduates of accredited schools and programs of public health who successfully pass their examination. If this certification becomes common, the debate will move to other questions such as (a) can those who lack a degree from a school of public health be certified through the same examination, or a similar one; (b) how will this general certificate relate to specialized areas of public health practice which are also learned elsewhere; and (c) how will we assess the public health competence of public health workers who do not have a professional education?
The Behavioral Risk Factors Surveillance System: Past, Present, and Future
Authors: Mokdad Ali H.
Published: January 2009

The Behavioral Risk Factor Surveillance System (BRFSS) is a large state-based telephone survey. BRFSS is designed to monitor the leading risk factors for morbidity and mortality in the United States at the local, state, and national levels. The BRFSS has proven to be a powerful tool for building heath-promotion activities. However, the use of telephone-based, random-digit-dial (RDD) methods in public health surveys and surveillance is at a crossroads. Rapid changes in telecommunication, declines in participation rates, increases in the required level of effort and associated costs are becoming key challenges for BRFSS. To maintain the highest data quality and service to the local and state health departments, BRFSS has adopted an ongoing effort to improve coverage and response to the survey. This article provides an overview of the issues faced by BRFSS and the strategies in place to address them.
Best Proximity Sets and Equilibrium Pairs for a Finite Family of Multimaps
Authors: Al-Thagafi M. A. , Shahzad Naseer
Published: January 2009

We establish the existence of a best proximity pair for which the best proximity set is nonempty for a finite family of multimaps whose product is either an "Equation missing"-multimap or a multimap "Equation missing" such that both "Equation missing" and "Equation missing" are closed and have the KKM property for each Kakutani multimap "Equation missing". As applications, we obtain existence theorems of equilibrium pairs for free 1-person games as well as for free 1-person games. Our results extend and improve several well-known and recent results.
Expression and prognostic significance of kallikrein-related peptidase 8 protein levels in advanced ovarian cancer by using automated quantitative analysis
Authors: Scorilas Andreas , Markakis Sonia , Kowalski Diane , Camp Robert L. , Diamandis Eleftherios P. , Dimopoulos Meletios A. , Kountourakis Panteleimon , Psyrri Amanda
Published: January 2009

Kallikrein-related peptidases, a subgroup of the serine protease enzyme family, are considered to be important prognostic biomarkers in cancer. In this study we sought to determine the prognostic value of kallikrein-related peptidase 8 (KLK8,hK8,KLK-8) in ovarian cancer using a novel method of compartmentalised in situ protein analysis. A tissue array composed of 150 advanced stage ovarian cancers, uniformly treated with surgical debulking followed by platinum-paclitaxel combination chemotherapy, was constructed. For the evaluation of kallikrein-related peptidase 8 protein expression, we used an immunofluorescence-based method of automated in situ quantitative protein analysis (AQUA). Mean follow-up time of the cohort was 34.35 months. One hundred twenty-six of 150 cases had sufficient tissue for AQUA analysis. There were significant correlations between tumour mask KLK8 protein expression levels and clinicopathological variables, including grade (p=0.0011), residual disease (p=0.0063) and clinical response to chemotherapy(p=0.0346). In univariate survival analysis there was a significant correlation between KLK8 tumour mask expression and five years progression-free survival, meanwhile it was not associated with five-year overall survival (p =0.0694). Specifically, low KLK8 expression correlated with better outcome (top vs. bottom quartile, p=0.0319). In multivariate survival analysis, adjusting for well-characterised prognostic variables, tumour KLK8 expression level retained its prognostic significance for progression-free survival (95%CI: 0.341–1.027, p=0.045). The possibility that KLK8 may be a suitable candidate as a diagnostic and prognostic marker warrants further investigation.
How useful is determination of anti-factor Xa activity to guide bridging therapy with enoxaparin?
Authors: Omran Heyder , Tripp Christian , Poetzsch Bernd , Hammerstingl Christoph
Published: January 2009

Low-molecular-weight heparins (LMWH) are commonly used as peri-procedural bridging anticoagulants. The usefulness of measurement of anti-factor Xa activity (anti-Xa) to guide bridging therapy with LMWH is unknown. It was the objective of this study to determine levels of anti-Xa during standard bridging therapy with enoxaparin, and to examine predictors for residual anti-Xa. Consecutive patients receiving enoxaparin at a dosage of 1 mg/kg body weight/12 hours for temporary interruption of phenprocoumon were prospectively enrolled to the study. Blood-samples were obtained 14 hours after LMWH-application immediately pre- procedurally. Procedural details, clinical and demographic data were collected and subsequently analyzed. Seventy patients were included (age 75.2 ± 10.8 years, Cr Cl 55.7 ± 21.7ml/min, body mass index [BMI] 27.1 ± 4.9). LMWH- therapy was for a mean of 4.2 ± 1.6 days; overall anti-Xa was 0.58 ± 0.32 U/ml. In 37 (52.8%) of patients anti-Xa was ≥0.5 U/ml, including 10 (14.3%) patients with anti-Xa > 1U/ml. Linear regression analysis of single variables and logistic multivariable regression analysis failed to prove a correlation between anti-Xa and single or combined factors. No major bleeding, no thromboembolism and four (5.7%) minor haemorrhages were observed. When bridging OAC with therapeutic doses of enoxaparin a high percentage of patients undergo interventions with high residual anti-Xa. The levels of anti-Xa vary largely and are independent of single or combined clinical variables. Since the anti-Xa-related outcome of patients receiving bridging therapy with LMWH is not investigated, no firm recommendation on the usefulness of monitoring of anti-Xa can be given at this stage.
Increased plasma von Willebrand factor antigen levels but normal von Willebrand factor cleaving protease (ADAMTS13) activity in preeclampsia
Authors: Rigó Jr János , Bõze Tamás , Derzsy Zoltán , Cervenak László , Makó Veronika , Gombos Tímea , Udvardy Miklós László , Hársfalvi Jolán , Prohászka Zoltán , Molvarec Attila
Published: January 2009

The activity of ADAMTS13, the von Willebrand factor (VWF) cleaving protease is low in several conditions, including HELLP (haemolysis, elevated liver enzymes, and low platelet count) syndrome. As HELLP syndrome develops in most cases on the basis of preeclampsia, our aim was to determine whether plasma ADAMTS13 activity is decreased in preeclampsia. Sixty-seven preeclamptic patients, 70 healthy pregnant women and 59 healthy non-pregnant women were involved in this case-control study. Plasma ADAMTS13 activity was determined with the FRETS-VWF73 assay, while VWF antigen (VWF:Ag) levels with an enzyme-linked immunosorbent assay. The multimeric pattern of VWF was analyzed by SDS-agarose gel electrophoresis. There was no significant difference in plasma ADAMTS13 activity between the preeclamptic and the healthy pregnant and non-pregnant groups (median [25–75 percentile]: 98.8 [76.5–112.8] %, 96.3 [85.6–116.2] % and 91.6 [78.5–104.4] %, respectively; p>0.05). However, plasma VWF:Ag levels were significantly higher in preeclamptic patients than in healthy pregnant and non-pregnant women (187.1 [145.6–243.1] % versus 129.3 [105.1–182.8] % and 70.0 [60.2–87.3] %, respectively; p<0.001). The multimeric pattern of VWF was normal in each group. Primiparas had lower plasma ADAMTS13 activity than multi-paras (92.6 [75.8–110.6] % versus 104.2 [92.1–120.8] %; p=0.011). No other relationship was found between clinical characteristics, laboratory parameters and plasma ADAMTS13 activity in either study group. In conclusion, plasma ADAMTS13 activity is normal in preeclampsia despite the increased VWF:Ag levels. However, further studies are needed to determine whether a decrease in plasma ADAMTS13 activity could predis-pose preeclamptic patients to develop HELLP syndrome.
Factor XIII-A subunit Val34Leu polymorphism is associated with the risk of thrombosis in patients with antiphospholipid antibodies and high fibrinogen levels
Authors: Red Gloria de la , Tàssies Dolores , Espinosa Gerard , Monteagudo Joan , Bové Albert , Plaza Joan , Cervera Ricard , Reverter Joan-Carles
Published: January 2009

Recent reports have described the factor XIII A subunit (FXIII-A) Val34Leu polymorphism as a protective factor against venous and arterial thrombosis. The aim of this study was to investigate the association between the FXIII-A Val34Leu polymorphism, its interaction with fibrinogen concentration, and thrombosis in patients with antiphospholipid antibodies (aPL). We included 172 consecutive patients with aPL: 88 with primary antiphospholipid syndrome (APS), 38 with APS associated with systemic lupus erythematosus (APS-SLE), 32 with SLE and aPL but without APS (SLE-aPL), and 14 asymptomatic individuals with aPL (A-aPL). The FXIII-A Val34Leu polymorphism was assessed by polymerase chain reaction techniques. We found no significant differences in FXIII-A Leu34 allele frequencies between primary APS (allele frequency 0.22), APS-SLE (0.23), SLE-aPL (0.22) and A-aPL (0.32) patients, or between patients with (0.21) and without thrombosis (0.26). FXIII-A Leu34 allele frequencies were significantly lower in patients with thrombosis and those in the upper fibrinogen tertile (>3.40 g/l) (allele frequency 0.07) compared with patients without thrombosis in the upper fibrinogen tertile (0.29) and patients with (0.29) and without (0.25) thrombosis in the mid- and lower fibrinogen tertiles. The FXIII-A Leu34 allele had a protective effect against thrombosis in patients in the upper fibrinogen tertile (odds ratio [OR]=0.20, 95% confidence interval [CI] 0.07–0.60) but not in those in the other tertiles (OR=1.20, 95% CI 0.67–2.16). The FXIII-A Leu34 allele seems to have a protective effect on the development of thrombosis in patients with aPL, but only in those with high plasma fibrinogen values.
Maturation of blood vessels by haematopoietic stem cells and progenitor cells: Involvement of apelin/APJ and angiopoietin/Tie2 interactions in vessel caliber size regulation
Authors: Kidoya Hiroyasu , Takakura Nobuyuki
Published: January 2009

Apelin is a recently-isolated bioactive peptide from bovine gastric extract. The gene encodes a protein of 77 amino acids, which can generate two active polypeptides, long (42–77) and short (65–77). Both peptides ligate and activate APJ, a G protein-coupled receptor expressed in the cardiovascular and central nervous systems. Although an essential role for the apelin/APJ system in blood vessel formation has been reported in Xenopus, its precise function in mammals is unclear. Blood vessel tube formation is accomplished by two main mechanisms: 1) single cell hollowing, in which a lumen forms within the cytoplasm of a single endothelial cell (EC), and 2) cord hollowing in which a luminal cavity is created de novo between ECs in a thin cylindrical cord. Molecular control of either single cell or cord hollowing has not been precisely determined. Angiopoietin-1 (Ang1) has been reported to induce enlargement of blood vessels. Apelin is produced from ECs upon activation of Tie2, a cognate receptor of Ang1, expressed on ECs. It has been suggested that apelin induces cord hollowing by promoting proliferation and aggregation/assembly of ECs. During angiogenesis, haematopoietic stem cells (HSCs) and progenitor cells (HPCs) are frequently observed in the perivascular region. They produce Ang1 and induce migration of ECs, resulting in a fine vascular network. Moreover, HSCs/HPCs can induce apelin production from ECs. Therefore, this review article posits that HSCs/HPCs regulate caliber size of blood vessels via apelin/APJ and Angiopoietin/Tie2 interactions.