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The stabilities of the trans (B) and cis (C) tautomeric ring forms that are experimentally observed in the ring- chain tautomeric interconversion of 1-alkyl-3-aryl-2,3-dihydro-1H-naphth[1,2-e][1,3]oxazines has been investigated. Stability differences are explained by the analysis of the natural bond orbital results for the lone pairs of electrons that are on the heteroatoms in the oxazine ring system and by regression analysis of the calculated 13C NMR chemical shift values.
Ionic liquids based on imidazolium, pyridinium, and alkylammonium salts were investigated as solvents in free radical polymerization of the model monomer n-butyl methacrylate. The properties of the ionic liquids were systematically varied by changing the length of the alkyl substituents on the cations, and by employing different anions such as tetrafluoroborate, hexafluorophosphate, tosylate, triflate, alkyl sulfates and dimethyl phosphate. Results were compared to analogous polymerizations in toluene and in bulk. The solvents have no detectable influence on polymer tacticity. However, the molar masses obtained and the degree of polymerization, respectively, are very sensitive to the choice of the solvent. The degrees of polymerization are significantly higher when polymerizations were carried out in ionic liquids compared to polymerization in toluene, and can even exceed the values obtained by bulk polymerization. Imidazolium salts unsubstituted at C-2 result in an increase in the degree of polymerization of the poly(butyl methacrylate) with increasing viscosity of these ionic liquids. Methyl substitution at C-2 of the imidazolium ion results in an increase in the viscosity of the ionic liquid and in a viscosity independent degree of polymerization of the poly(butyl methacrylate). Ionic liquids based on imidazolium salts seem preferable over pyridinium and alkylammonium salts because of the higher degree of polymerization of the poly(butyl methacrylate)s obtained in the imidazolium salts. The glass transition temperatures and thermal stabilities are higher for poly(butyl methacrylate)s synthesized in the ionic liquids compared to the polymer made in toluene
The occurrence of two individuals of Zu cristatus at 2 m depth in coastal waters of the Gulf of Castellamare (Tyrrhenian Sea, Italy) together with records of this rare pan-Oceanic mesopelagic species is reported. Analyses of two mitochondrial genes (12 s and 16 s; 936 bp) revealed a 2.6% sequence divergence between Mediterranean and Pacific (Japanese) samples of the species.
The concept of the virtual corporation (VC), which describes a modern form of collaboration among organizations, was introduced in the scientific discussion in the mid 1990th. The practice shows that VCs need new forms of governance because the traditional mechanisms of control, management, and steering are hardly applicable. Until now there is only a few research related to the question how to govern VC. The main problems to govern a VC are to coordinate the communication among dispersed partners and to motivate employees to actively involve themselves into the network. Open source projects are confronted with similar problems. As several governance mechanisms are already analyzed in this context, the authors analyze and adopt governance concepts from open source projects to extract a governance framework for virtual corporations. This new approach leads to innovative insights in governing virtual corporations by using community techniques as an appropriate way for communication and collaboration purposes.
Public Private Partnerships as an Accelerator of Broadband Diffusion? Findings from Case Studies,
(2006)
Bushbuck (Tragelaphus scriptus) often deposit faeces at specific localised defecation sites (LDS). We tested whether LDS have a function in the context of parasite avoidance. In a population of bushbuck in Queen Elizabeth National Park, Uganda, seven radio-collared individuals were observed. We recorded feeding behaviour inside and outside LDS. Furthermore, pasture contamination with gastro-intestinal tract parasites inside and outside LDS was examined. There were significant differences between the expected and the observed feeding rates inside LDS, but, contrary to our prediction, the bushbuck increased their feeding rate inside LDS. There was no significant difference in the parasite contamination of pastures inside and outside LDS. We discuss the hypothesis that LDS mainly serve a social function in bushbuck communities, whereas parasite avoidance seems to play a minor or no role
Charles Horton Cooley
(2006)
In this paper a self-checking carry select adder is proposed. The duplicated adder blocks which are inherent to a carry select adder without error detection are checked modulo 3. Compared to a carry select adder without error detection the delay of the MSB of the sum of the proposed adder does not increase. Compared to a self-checking duplicated carry select adder the area is reduced by 20%. No restrictions are imposed on the design of the adder blocks
The work presents low signal dielectric spectra of gold/copper phthalocyanine/magnesium and gold/copper phthalocyanine/gold sandwich systems in the 25 Hz-1 MHz frequency range. The performed analysis enables us to distinguish the electrode resistance and the lattice polarization from processes related with electric transport, such as charge carrier relaxation at space charge region of a barrier and charge carrier injection in dielectric response.
Brinton, L. J., Traugott, E. C., Lexicalization and Language Change; Cambridge, Univ.-Press, 2006
(2006)
Grammaticalization
(2006)
Requirements for an integration of methods analyzing social issues in knowledge organizations
(2006)
Peridinin-chlorophyll a-protein (PCP) is a unique antenna complex in dinoflagellates that employs peridinin (a carotenoid) as its main light-harvesting pigment. Strong excitonic interactions between peridinins, as well as between peridinins and chlorophylls (Chls) a, can be expected from the short intermolecular distances revealed by the crystal structure. Different experimental approaches of nonlinear polarization spectroscopy in the frequency domain (NLPF) were used to investigate the various interactions between pigments in PCP of Amphidinium carterae at room temperature. Lineshapes of NLPF spectra indicate strong excitonic interactions between the peridinin's optically allowed S-2 (1Bu(+)) states. A comprehensive subband analysis of the distinct NLPF spectral substructure in the peridinin region allows us to assign peridinin subbands to the two Chls a in PCP having different S-1-state lifetimes. Peridinin subbands at 487, 501, and 535 nm were assigned to the longer-lived Chl, whereas a peridinin subband peaking at 515 nm was detected in both clusters. Certain peridinin(s), obviously corresponding to the subband centered at 487 nm, show(s) specific (possibly Coulombic?) interaction between the optically dark S-1(2A(g)(-)) and/or intramolecular charge- transfer (ICT) state and S-1 of Chl a. The NLPF spectrum, hence, indicates that this peridinin state is approximately isoenergetic or slightly above S-1 of Chl a. A global subband analysis of absorption and NLPF spectra reveals that the Chl a Q(y)-band consists of two subbands ( peaking at 669 and 675 nm and having different lifetimes), confirmed by NLPF spectra recorded at high pump intensities. At the highest applied pump intensities an additional band centered at <= 660 nm appears, suggesting-together with the above results-an assignment to a low-dipole moment S-0-> S-1/ICT transition of peridinin
Calpain 1-gamma filamin interaction in muscle cells : a possible in situ regulation by PKC-alpha
(2006)
A localized dehydration zone, Sondrum stone quarry, Halmstad, SW Sweden, consists of a central, 1 m wide granitic pegmatoid dyke, on either side of which extends a 2.5-3 m wide dehydration zone (650-700 degrees C; 800 MPa; orthopyroxene-clinopyroxene-biotite-amphibole-garnet) overprinting a local migmatized granitic gneiss (amphibole-biotite- garnet). Whole-rock chemistry indicates that dehydration of the granitic gneiss was predominantly isochemical. Exceptions include [Y + heavy rare earth elements (HREE)], Ba, Sr, and F, which are markedly depleted throughout the dehydration zone. Systematic trends in the silicate and fluorapatite mineral chemistry across the dehydration zone include depletion in Fe, (Y + HREE), Na, K, F, and Cl, and enrichment in Mg, Mn, Ca, and Ti. Fluid inclusion chemistry is similar in all three zones and indicates the presence of a fluid containing CO2, NaCl, and H2O components. Water activities in the dehydration zone average 0.36, or XH2O = 0.25. All lines of evidence suggest that the formation of the dehydration zone was due to advective transport of a CO2-rich fluid with a minor NaCl brine component originating from a tectonic fracture. Fluid infiltration resulted in the localized partial breakdown of biotite and amphiboles to pyroxenes releasing Ti and Ca, which were partitioned into the remaining biotite and amphibole, as well as uniform depletion in (Y + HREE), Ba, Sr, Cl, and F. At some later stage, H2O-rich fluids (H2O activity > 0.8) gave rise to localized partial melting and the probable injection of a granitic melt into the tectonic fracture, which resulted in the biotite and amphibole recording a diffusion profile for F across the dehydration zone into the granitic gneiss as well as a diffusion profile in Fe, Mn, and Mg for all Fe-Mg silicate minerals within 100 cm of the pegmatoid dyke
The reaction of methyl acridin-9-ylthiosemicarbazide under basic conditions with methyl bromoacetate resulted in a 1,3-thiazolin-4-one structure as provided by X-ray crystallography. The structure forced a re-evaluation of the reactant methyl acridin-9-ylthiosemicarbazide, originally thought to be 2-methyl 4-acridin-9-ylthiosemicarbazide based on synthetic expectations, but which when examined by X-ray crystallography was found to be in fact the isomeric 2- methyl 1-acridin-9-ylthiosemicarbazide resulting from rearrangement via a spiro form which it is in equilibrium with in solution. The product resulting from reaction with methyl iodide was also studied and the previously reported semicarbazide produced by reaction with MNO was re-examined. In both cases, the 1,2 isomer rather than the 2,4 isomer was found to be present based on the sign of the 3JCH3,N11 coupling. Full characterization of the compounds was rendered by 1H, 13C, and 15N solution-state NMR, and in the solid state, by both 13C and 15N NMR.
An approach is presented for coupled chaotic systems with weak coherent motion, from which we estimate the upper bound value for the absolute phase difference in phase synchronous states. This approach shows that synchronicity in phase implies synchronicity in the time of events, a characteristic explored to derive an equation to detect phase synchronization, based on the absolute difference between the time of these events. We demonstrate the potential use of this approach for the phase coherent and the funnel attractor of the Rossler system, as well as for the spiking/bursting Rulkov map.
We investigate the usage of rule dependency graphs and their colorings for characterizing and computing answer sets of logic programs. This approach provides us with insights into the interplay between rules when inducing answer sets. We start with different characterizations of answer sets in terms of totally colored dependency graphs that differ ill graph-theoretical aspects. We then develop a series of operational characterizations of answer sets in terms of operators on partial colorings. In analogy to the notion of a derivation in proof theory, our operational characterizations are expressed as (non-deterministically formed) sequences of colorings, turning an uncolored graph into a totally colored one. In this way, we obtain an operational framework in which different combinations of operators result in different formal properties. Among others, we identify the basic strategy employed by the noMoRe system and justify its algorithmic approach. Furthermore, we distinguish operations corresponding to Fitting's operator as well as to well-founded semantics
Phonological specificity of early lexical representations in German 19-month-olds at risk for SLI
(2006)
The recognition of the prosodic focus position in German-Learning Infants from 4 to 14 Months
(2006)
Elastic properties and electromechanical coupling factor of inflated polypropylene ferroelectrets
(2006)
Relaxation processes at the glass transition in polyamide 11 : From rigidity to viscoelasticity
(2006)
Skill Management
(2006)
Beauzée, Nicolas (1717-1789)
(2006)
Hervás y Panduro, Lorenzo
(2006)
Molecular identification and functional characterization of an adenylyl cyclase from the honeybee
(2006)
Cyclic AMP (cAMP) serves as an important messenger in virtually all organisms. In the honeybee (Apis mellifera), cAMP-dependent signal transduction has been implicated in behavioural processes as well as in learning and memory. Key components of cAMP-signalling cascades are adenylyl cyclases. However, the molecular identities and biochemical properties of adenylyl cyclases are completely unknown in the honeybee. We have cloned a cDNA (Amac3) from honeybee brain that encodes a membrane-bound adenylyl cyclase. The Amac3 gene is an orthologue of the Drosophila ac39E gene. The corresponding proteins share an overall amino acid similarity of approximately 62%. Phylogenetically, AmAC3 belongs to group 1 adenylyl cyclases. Heterologously expressed AmAC3 displays basal enzymatic activity and efficient coupling to endogenous G protein signalling pathways. Stimulation of beta-adrenergic receptors induces AmAC3 activity with an EC50 of about 3.1 mu m. Enzymatic activity is also increased by forskolin (EC50 approximately 15 mu m), a specific agonist of membrane-bound adenylyl cyclases. Similar to certain biogenic amine receptor genes of the honeybee, Amac3 transcripts are expressed in many somata of the brain, especially in mushroom body neurones. These results suggest that the enzyme serves in biogenic amine signal transduction cascades and in higher brain functions that contribute to learning and memory of the bee
Push-pull alkenes are substituted alkenes with one or two electron-donating substituents on one end of C=C double bond and with one or two electron-accepting substituents at the other end. Allowance for pi-electron delocalization leads to the central C=C double bond becoming ever more polarized and with rising push-pull character, the pi-bond order of this double bond is reduced and, conversely, the corresponding pi-bond orders of the C-Don and C- Ace bonds are accordingly increased. This push-pull effect is of decisive influence on both the dynamic behavior and the chemical reactivity of this class of compounds and thus it is Of Considerable interest to both determine and to quantify the inherent push-pull effect. previously, the barriers to rotation about the C=C, C-Don and/or C-Acc partial double bonds (Delta G(not equal), as determined by dynamic NMR spectroscopy) or the C-13 chemical shift difference of the polarized C=C partial double bond (Delta delta(C=C)) were employed for this purpose, However, these parameters can have serious limitations, viz. the barriers can be immeasurable on the NMR timescale (either by being too high or too low-, heavily-biased conformers are present, etc.) or Delta delta(C=C) behaves in a non-additive manner with respect to the combination of the four substituents. Hence, a general parameter to quantify the push-pull effect is not yet available. Ab initio MO calculations on a collection of compounds, together with NBO analysis, provided valuable information on the structure, bond energies, electron occupancies and bonding/antibonding interactions. In addition to Delta G(C=C)(not equal) (either experimentally determined or theoretically calculated) and Delta delta(C=C), the bond length of the C=C partial double bond was also examined and it proved to be a reliable parameter to quantify the push-pull effect. Equally so, the quotient of the occupation numbers of the antibonding and bonding pi orbitals of the central C=C partial double bond ( pi*(C=C)/pi(C=C) ) could also be employed for this purpose
The nasal roof cartilage of a neonate sperm whale (Physeter macrocephalus) was examined by gross dissection and routine histology. This cartilage is part of the embryonic Tectum nasi and is a critical feature in the formation of the massive sperm whale forehead. In neonates as well as in adults, the blade-like nasal roof cartilage extends diagonally through the huge nasal complex from the bony nares to the blowhole on the left side of the rostral apex of the head. It accompanies the left nasal passage along its entire length, which may reach several meters in adult males. The tissue of the nasal roof cartilage in the neonate whale shows an intermediate state of development. For example, in embryos and fetuses, the nasal roof cartilage consists of hyaline cartilage, but in adult sperm whales, it also includes elastic fibers. In our neonate sperm whale, the nasal roof cartilage already consisted of adult-like elastic cartilage. In addition, the active or growing, layer of the perichondrium was relatively thick compared to that of fetuses, and a large number of straight, elastic fibers that were arranged perpendicularly to the long axis of the nasal roof cartilage were present. These neonatal features call be interpreted as characteristics of immature and growing cartilaginous tissue. An important function of the nasal roof cartilage may be the stabilization of the left nasal passage, which is embedded within the soft tissue of the nasal complex. The nasal roof cartilage with its elastic fibers may keep the nasal passage open and prevent its collapse from Bernoulli forces during inhalation. Additionally, the intrinsic tension of the massive nasal musculature may be a source of compression on the nasal roof cartilage and could explain its hyaline character in the adult. In our neonate specimen, in contrast, the cartilaginous rostrum (i.e., mesorostral cartilage) consisted of hyaline cartilage with an ample blood supply. The cartilaginous rostrum does not change its histological characteristics during development, but its function In adults is still not understood.
An experimental evaluation of a safer sex promotion leaflet was undertaken to assess its capacity to change antecedent cognitions of condom use. The leaflet was identified in a previous study as addressing research-based cognitive antecedents of condom use. A pre-post-test experimental study including three conditions was conducted: (a) presentation of the leaflet; (b) presentation of the leaflet plus incentive for systematic processing; (c) no-leaflet control. The leaflet was evaluated in terms of its capacity to change eight cognitive correlates of condom use identified in a recent meta-analysis. The sample consisted of 230 tenth-grade students. Following baseline assessments, leaflet-induced change was measured immediately following the intervention and at a follow up 4 weeks post-intervention. The target leaflet alone did not result in significant changes in the cognitive antecedents of condom use compared with the control condition. However, in combination with an incentive for systematic processing, the target leaflet had a greater impact on cognitive antecedents than the no-leaflet control condition. The findings are discussed with regard to the development and evaluation of research-based health-promotion materials
Business process management
(2006)
Synchronization
(2006)
With the next generation Internet protocol IPv6 at the horizon, it is time to think about how applications can migrate to IPv6. Web traffic is currently one of the most important applications in the Internet. The increasing popularity of dynamically generated content on the World Wide Web, has created the need for fast web servers. Server clustering together with server load balancing has emerged as a promising technique to build scalable web servers. The paper gives a short overview over the new features of IPv6 and different server load balancing technologies. Further, we present and evaluate Loaded, an user-space server load balancer for IPv4 and IPv6 based on Linux.
This contribution describes a generator of stochastic time series of daily precipitation for the interior of Israel from c. 90 to 900 mm mean annual precipitation (MAP) as a tool for studies of daily rain variability. The probability of rainfall on a given day of the year is described by a regular Gaussian peak curve function. The amount of rain is drawn randomly from an exponential distribution whose mean is the daily mean rain amount (averaged across years for each day of the year) described by a flattened Gaussian peak curve. Parameters for the curves have been calculated from monthly aggregated, long-term rain records from seven meteorological stations. Parameters for arbitrary points on the MAP gradient are calculated from a regression equation with MAP as the only independent variable. The simple structure of the generator allows it to produce time series with daily rain patterns that are projected under climate change scenarios and simultaneously control MAP. Increasing within-year variability of daily precipitation amounts also increases among-year variability of MAP as predicted by global circulation models. Thus, the time series incorporate important characteristics for climate change research and represent a flexible tool for simulations of daily vegetation or surface hydrology dynamics.
Calpain 1-gamma filamin interaction in muscle cells : a possible in situ regulation by PKC-alpha
(2006)
Calpains are a family of calcium-dependant cysteine-proteases involved in cytoskeleton remodelling and muscle differentiation. In a recent study, we observed the presence of calpain I in the muscle contractile apparatus and specifically in the N1- and N2-fines. This calpain isoform was found to be involved in the degradation of muscle fibres via proteolysis of key proteins in Z-disk and costameric junctions. The goal of this study was to determine whether gamma-filamin - a specific muscle isoform of the filamin family - is a calpain, I substrate and to characterise this interaction. gamma-Filamin is a major muscle architectural protein located in the Z-fine and under the sarcolemmal membrane. This protein is a component of the chain binding the sarcolemma to the sarcomeric structure. In this study, we found that gamma-filamin formed a stable complex in vitro and in cells with calpain I in the absence of calcium stimulation. We also located the binding domains in the C-terminus of gamma-filamin with a cleavage site between serine 2626 and serine 2627 in the hinge 2 region. The catalytic (80 kDa) and regulatory (28 kDa) subunits of calpain I are both involved in high affinity binding at gamma-filamin. Moreover, we showed that phosphorylation of the filamin C- terminus domain by PKC alpha protected gamma-filamin against proteolysis by calpain I in COS cells. Stimulation of PKC activity in myotubes, prevented gamma-filamin proteolysis by calpain and resulted in an increase in myotube adhesion.
Many real-world networks are characterized by adaptive changes in their topology depending on the state of their nodes. Here we study epidemic dynamics on an adaptive network, where the susceptibles are able to avoid contact with the infected by rewiring their network connections. This gives rise to assortative degree correlation, oscillations, hysteresis, and first order transitions. We propose a low-dimensional model to describe the system and present a full local bifurcation analysis. Our results indicate that the interplay between dynamics and topology can have important consequences for the spreading of infectious diseases and related applications
An Extended Query language for action languages (and its application to aggregates and preferences)
(2006)
In this article, we consider high-dimensional data which contains a low-dimensional non-Gaussian structure contaminated with Gaussian noise and propose a new linear method to identify the non-Gaussian subspace. Our method NGCA (Non-Gaussian Component Analysis) is based on a very general semi-parametric framework and has a theoretical guarantee that the estimation error of finding the non-Gaussian components tends to zero at a parametric rate. NGCA can be used not only as preprocessing for ICA, but also for extracting and visualizing more general structures like clusters. A numerical study demonstrates the usefulness of our method
We report a noise-memory induced phase transition in an array of oscillatory neural systems, which leads to the suppression of synchronous oscillations and restoration of excitable dynamics. This phenomenon is caused by the systematic contributions of temporally correlated parametric noise, i.e., possessing a memory, which stabilizes a deterministically unstable fixed point. Changing the noise correlation time, a reentrant phase transition to noise- induced excitability is observed in a globally coupled array. Since noise-induced excitability implies the restoration of the ability to transmit information, associated spatiotemporal patterns are observed afterwards. Furthermore, an analytic approach to predict the systematic effects of exponentially correlated noise is presented and its results are compared with the simulations