bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF THE ISOVECTOR PAIRING EFFECT ON NUCLEAR STATISTICAL QUANTITIES IN N ≈ Z EVEN–EVEN SYSTEMS
Authors: BELABBAS M. , FELLAH M. , ALLAL N. H. , BENHAMOUDA N. , AMI I. , OUDIH M. R.
Published: November 2010

The influence of the isovector neutron–proton (np) pairing effect on nuclear statistical quantities is studied in N ≈ Z even–even systems. Expressions of the energy, the entropy, and the heat capacity are established using a recently proposed temperature-dependent isovector pairing gap equations. They generalize the conventional finite temperature BCS (FTBCS) ones. The model is first numerically tested using the schematic one-level model. As a second step, realistic cases are considered using the single-particle energies of a deformed Woods–Saxon mean-field. It is shown that: (i) the gap parameter Δnp(T) behaves like Δtt(T), t = n, p, in the conventional FTBCS model and the critical temperature value Tcnp is such as Tcnp<Tcp<Tcn; (ii) the behavior of Δtt(T), t = n, p in the present model is different from that of the FTBCS one. This fact leads to a systematic discrepancy between the predictions of both models in the Tcnp<T<Tcn region for all studied statistical quantities; and (iii) in the 0≤T≤Tcnp region, the np pairing effect on the energy is a lowering of about 1%, on average, for all considered nuclei. Dealing with the entropy and the heat capacity, the np pairing effect appears only if the Tcnp value is sufficiently important.
Monadic datalog over finite structures of bounded treewidth
Authors: Gottlob Georg , Pichler Reinhard , Wei Fang
Published: November 2010

Bounded treewidth and monadic second-order (MSO) logic have proved to be key concepts in establishing fixed-parameter tractability results. Indeed, by Courcelle's Theorem we know that any property of finite structures, which is expressible by an MSO sentence, can be decided in linear time (data complexity) if the structures have bounded treewidth. In principle, Courcelle's Theorem can be applied directly to construct concrete algorithms by transforming the MSO evaluation problem into a tree language recognition problem. The latter can then be solved via a finite tree automaton (FTA). However, this approach has turned out to be problematical, since even relatively simple MSO formulae may lead to a “state explosion” of the FTA.

In this work we propose monadic datalog (i.e., datalog where all intentional predicate symbols are unary) as an alternative method to tackle this class of fixed-parameter tractable problems. We show that if some property of finite structures is expressible in MSO then this property can also be expressed by means of a monadic datalog program over the
decomposed structure
: we mean by this that the original structure is augmented with new elements and new relations that encode one of its tree decompositions. In the first place, we thus compare the expressive power of two query languages. However, we also show that the resulting fragment of datalog can be evaluated in linear time (both with respect to the program size and with respect to the data size). Hence, our transformation of an MSO query into a monadic datalog program yields an alternative proof of Courcelle's Theorem. In order to actually construct efficient algorithms for problems whose tractability is due to Courcelle's Theorem, we propose to use a fragment of full (i.e., not necessarily monadic) datalog which allows for a succinct representation of the corresponding monadic datalog programs and for an efficient execution. This new approach is put to work by devising datalog programs for the 3-Colorability problem of graphs and for the PRIMALITY problem of relational schemas (i.e., testing if some attribute in a relational schema is part of a key). We also report on experimental results with a prototype implementation.
A theory of sampling for continuous-time metric temporal logic
Authors: Furia Carlo A. , Rossi Matteo
Published: November 2010

This article revisits the classical notion of sampling in the setting of real-time temporal logics for the modeling and analysis of systems. The relationship between the satisfiability of metric temporal logic (MTL) formulas over continuous-time models and over discrete-time models is studied. It is shown to what extent discrete-time sequences obtained by sampling continuous-time signals capture the semantics of MTL formulas over the two time domains. The main results apply to “flat” formulas that do not nest temporal operators and can be applied to the problem of reducing the verification problem for MTL over continuous-time models to the same problem over discrete time, resulting in an automated partial practically efficient discretization technique.
A random-sampling-based algorithm for learning intersections of halfspaces
Authors: Vempala Santosh S.
Published: November 2010

We give an algorithm to learn an intersection of
k
halfspaces in
R

n

whose normals span an
l
-dimensional subspace. For any input distribution with a
logconcave
density such that the bounding hyperplanes of the
k
halfspaces pass through its mean, the algorithm (ϵ,δ)-learns with time and sample complexity bounded by (
nkl
/ϵ)

O(l)

log 1/ϵ δ. The hypothesis found is an intersection of
O(k
log (1/ϵ)) halfspaces. This improves on Blum and Kannan's algorithm for the uniform distribution over a ball, in the time and sample complexity (previously doubly exponential) and in the generality of the input distribution.
Streaming of high-resolution progressive meshes over the internet
Authors: Wei Cheng
Published: November 2010

High-resolution 3D meshes are increasingly available in networked applications, such as digital museum, online game, and virtual reality. The amount of data constituting a high-resolution 3D mesh can be huge, leading to long downloading time. To reduce the waiting time of users, a common technique for remote viewing is progressive streaming, which allows a low-resolution version of the mesh to be transmitted and rendered with low latency. The quality of the transmitted mesh is incrementally improved by continuously transmitting the refinement information.
Synaptic Properties of Thalamic Input to Layers 2/3 and 4 of Primary Somatosensory and Auditory Cortices
Authors: Viaene Angela N. , Petrof Iraklis , Sherman S. Murray
Published: November 2010

We studied the synaptic profile of thalamic inputs to cells in layers 2/3 and 4 of primary somatosensory (S1) and auditory (A1) cortices using thalamocortical slices from mice age postnatal days 10–18. Stimulation of the ventral posterior medial nucleus (VPM) or ventral division of the medial geniculate body (MGBv) resulted in two distinct classes of responses. The response of all layer 4 cells and a minority of layers 2/3 cells to thalamic stimulation was Class 1, including paired-pulse depression, all-or-none responses, and the absence of a metabotropic component. On the other hand, the majority of neurons in layers 2/3 showed a markedly different, Class 2 response to thalamic stimulation: paired-pulse facilitation, graded responses, and a metabotropic component. The Class 1 and Class 2 response characteristics have been previously seen in inputs to thalamus and have been described as drivers and modulators, respectively. Driver input constitutes a main information bearing pathway and determines the receptive field properties of the postsynaptic neuron, whereas modulator input influences the response properties of the postsynaptic neuron but is not a primary information bearing input. Because these thalamocortical projections have comparable properties to the drivers and modulators in thalamus, we suggest that a driver/modulator distinction may also apply to thalamocortical projections. In addition, our data suggest that thalamus is likely to be more than just a simple relay of information and may be directly modulating cortex.
Heading in a New Direction: Drug Permeability in Breast Cancer Brain Metastasis
Authors: Sledge George W.
Published: November 2010

Systemic therapies for breast cancer brain metastasis are largely unsuccessful. Mouse models of brain metastasis show significant heterogeneity in uptake of paclitaxel and doxorubicin, with average levels more than those seen in normal brain tissue, but significantly less than in metastases to other organs. Clin Cancer Res; 16(23); 5605–7. ©2010 AACR.
Upfront immunization with autologous recombinant idiotype Fab fragment without prior cytoreduction in indolent B-cell lymphoma
Authors: Navarrete Marcelo A. , Heining-Mikesch Kristina , Schüler Frank , Bertinetti-Lapatki Cristina , Ihorst Gabriele , Keppler-Hafkemeyer Andrea , Dölken Gottfried , Veelken Hendrik
Published: November 2010

Idiotype vaccination for follicular lymphoma is primarily being developed as remission consolidation after chemotherapy. We investigated idiotype vaccination as primary intervention for treatment-naive indolent B-cell lymphoma and in a separate cohort as remission consolidation after chemotherapy to assess immunization-induced immune responses in relation to progression-free survival (German Clinical Trials Register, DRKS00000227). Twenty-one patients in each cohort received 6 intradermal injections of adjuvanted recombinant idiotype Fab fragment (FabId); 76% of patients in both groups developed anti-idiotype antibodies and/or cellular immunity as measured by enzyme-linked immunosorbent assay and interferon-γ ELISpot. In treatment-naive patients, only cellular responses correlated with superior progression-free survival (P < .002) and durable objective remissions (P = .04). Immunization-induced T cells recognized hypermutated or complementarity-determining region 3 epitopes. After remission consolidation immunization, induction of anti-idiotype antibodies correlated with progression-free survival. Low B-cell counts after rituximab therapy predicted for failure to develop anti-idiotype antibodies. These results are similar to published trials showing an association of humoral immunity with control of residual lymphoma. In contrast, effective immunity against untreated lymphoma appears to be dependent on idiotype-specific T cells. Sustained remissions in patients with vaccination-induced cellular immunity suggest clinical benefit and warrant a randomized comparison of this vaccine with expectant management for asymptomatic follicular lymphoma.
Development and validation of a FACS-based lipoprotein localization screen in the Lyme disease spirochete Borrelia burgdorferi
Authors: Kumru Ozan S , Schulze Ryan J , Slusser Joyce G , Zückert Wolfram R
Published: November 2010

Background

In our previous studies on lipoprotein secretion in the Lyme disease spirocheteBorrelia burgdorferi, we used monomeric red fluorescent protein 1 (mRFP1) fused to specifically mutated outer surface protein A (OspA) N-terminal lipopeptides to gather first insights into lipoprotein sorting determinants. OspA:mRFP1 fusions could be detected by epifluorescence microscopy both in the periplasm and on the bacterial surface. To build on these findings and to complement the prior targeted mutagenesis approach, we set out to develop a screen to probe a random mutagenesis expression library for mutants expressing differentially localized lipoproteins.

Results

A Glu-Asp codon pair in the inner membrane-localized OspA20:mRFP1 fusion was chosen for mutagenesis since the two negative charges were previously shown to define the phenotype. A library of random mutants in the two codons was generated and expressed inB. burgdorferi.In situsurface proteolysis combined with fluorescence activated cell sorting (FACS) was then used to screen for viable spirochetes expressing alternative subsurface OspA:mRFP1 fusions. Analysis of 93 clones randomly picked from a sorted cell population identified a total of 43 distinct mutants. Protein localization assays indicated a significant enrichment in the selected subsurface phenotype. Interestingly, a majority of the subsurface mutant proteins localized to the outer membrane, indicating their impairment in "flipping" through the outer membrane to the spirochetal surface. OspA20:mRFP1 remained the protein most restricted to the inner membrane.

Conclusions

Together, these results validate this FACS-based screen for lipoprotein localization and suggest a rather specific inner membrane retention mechanism involving membrane anchor-proximal negative charge patches in this modelB. burgdorferilipoprotein system.
Aspergillus fumigatus allergen expression is coordinately regulated in response to hydrogen peroxide and cyclic AMP
Authors: Fraczek Marcin G , Rashid Rifat , Denson Marian , Denning David W , Bowyer Paul
Published: November 2010

Background

A. fumigatus has been associated with a wide spectrum of allergic disorders such as ABPA or SAFS. It is poorly understood what allergens in particular are being expressed during fungal invasion and which are responsible for stimulation of immune responses. Study of the dynamics of allergen production by fungi may lead to insights into how allergens are presented to the immune system.

Methods

Expression of 17 A. fumigatus allergen genes was examined in response to various culture conditions and stimuli as well as in the presence of macrophages in order to mimic conditions encountered in the lung.

Results

Expression of 14/17 allergen genes was strongly induced by oxidative stress caused by hydrogen peroxide (Asp f 1, -2, -4, -5, -6, -7, -8, -10, -13, -17 and -18, all >10-fold and Asp f 11, -12, and -22, 5-10-fold) and 16/17 allergen genes were repressed in the presence of cAMP. The 4 protease allergen genes (Asp f -5, -10, -13 and -18) were expressed at very low levels compared to the comparator (β-tubulin) under all other conditions examined. Mild heat shock, anoxia, lipid and presence of macrophages did not result in coordinated changes in allergen gene expression. Growth on lipid as sole carbon source contributed to the moderate induction of most of the allergen genes. Heat shock (37°C > 42°C) caused moderate repression in 11/17 genes (Asp f 1, -2, -4, -5, -6, -9, -10, -13, -17, -18 and -23) (2- to 9-fold), which was mostly evident for Asp f 1 and -9 (~9-fold). Anaerobic stress led to moderate induction of 13/17 genes (1.1 to 4-fold) with one, Asp f 8 induced over 10-fold when grown under mineral oil. Complex changes were seen in gene expression during co-culture of A. fumigatus with macrophages.

Conclusions

Remarkable coordination of allergen gene expression in response to a specific condition (oxidative stress or the presence of cAMP) has been observed, implying that a single biological stimulus may play a role in allergen gene regulation. Interdiction of a putative allergen expression induction signalling pathway might provide a novel therapy for treatment of fungal allergy.
State-Dependent Firing Determines Intrinsic Dendritic Ca2+Signaling in Thalamocortical Neurons
Authors: Errington Adam C. , Renger John J. , Uebele Victor N. , Crunelli Vincenzo
Published: November 2010

Activity-dependent dendritic Ca2+signals play a critical role in multiple forms of nonlinear cellular output and plasticity. In thalamocortical neurons, despite the well established spatial separation of sensory and cortical inputs onto proximal and distal dendrites, respectively, little is known about the spatiotemporal dynamics of intrinsic dendritic Ca2+signaling during the different state-dependent firing patterns that are characteristic of these neurons. Here we demonstrate that T-type Ca2+channels are expressed throughout the entire dendritic tree of rat thalamocortical neurons and that they mediate regenerative propagation of low threshold spikes, typical of, but not exclusive to, sleep states, resulting in global dendritic Ca2+influx. In contrast, actively backpropagating action potentials, typical of wakefulness, result in smaller Ca2+influxes that can temporally summate to produce dendritic Ca2+accumulations that are linearly related to firing frequency but spatially confined to proximal dendritic regions. Furthermore, dendritic Ca2+transients evoked by both action potentials and low-threshold spikes are shaped by Ca2+uptake by sarcoplasmic/endoplasmic reticulum Ca2+ATPases but do not rely on Ca2+-induced Ca2+release. Our data demonstrate that thalamocortical neurons are endowed with intrinsic dendritic Ca2+signaling properties that are spatially and temporally modified in a behavioral state-dependent manner and suggest that backpropagating action potentials faithfully inform proximal sensory but not distal corticothalamic synapses of neuronal output, whereas corticothalamic synapses only “detect” Ca2+signals associated with low-threshold spikes.
Arthrodendron maguricum n. sp., a new larger agglutinated foraminifer from the Eocene Magura flysch of the Polish Carpathians and its relationship to komokiaceans and trace fossils
Authors: Kaminski Michael A. , Uchman Alfred , Rindsberg Andrew K.
Published: November 2010

Arthrodendron maguricum n. sp. is described from deep-sea flysch of the lower Eocene Życzanów Conglomerate Member of the Szczawnica Formation (Magura Unit) in the Polish Carpathians. Arthrodendron maguricum is a larger agglutinated foraminifer showing regular, tubular chambers that may branch dichotomously. Its wall is tripartite and composed of an outer organic-rich layer, a main agglutinated layer, and an internal organic-rich layer. The organism evidently lived as epibenthos on the muddy sea floor. Because of their branching morphology and comparatively large dimensions, larger agglutinated foraminifera of the genus Arthrodendron have previously been confused with algae and trace fossils. Care should be taken in such cases to resolve the agglutinated wall and chambers of this deep-water agglutinated foraminifer. Arthrodendron maguricum displays superficial similarities to some modern komokiaceans, especially to Septuma. Further investigations are needed for clarification of their affinities and possible taxonomic consequences.
Pseudomarssonella Redmond 1965 (Foraminifera) and related taxa from the Jurassic platform carbonate succession of the Central Taurides, S Turkey: its phylogenetic relation with the subfamily Paleopfenderininae
Authors: Tasli Kemal , Altiner Demir
Published: November 2010

Pseudomarssonella and related taxa have been recorded in the upper part of the Redmondoides lugeoni/Redmondoides cf. rotundatus Zone, Paleopfenderina trochoidea-salernitana and Kurnubia ex. gr. palastiniensis zones, and the lower half of the Clypeina jurassica Zone, from the Bathonian to the lower Tithonian of the Central Taurides (S Turkey) inner platform carbonate succession. A tentative phylogenetic tree of the Jurassic pfenderinids (paleopfenderins) is given in this study. The Paleopfenderininae are suggested to have evolved from PseudomarssonellaRedmond 1965 which might have diverged from RedmondoidesBanneret al. 1991 or RiyadhellaRedmond 1965. This evolution was carried out during the early Bathonian by the acquisition of accessory, cribrate apertural plate and more numbers of chambers per whorl. Pseudomarssonella has been removed from the family Chrysalidinidae (subfamily Paravalvulininae) since it is phylogenetically and taxonomically separated from Paravalvulina, which is fundamentally triserial, has cribrate septal flap as a prolongation of septum and has no secondary infillings. Herein it is placed into the family Pfenderinidae, subfamily Paleopfenderininae.
An ichthyosaur skull from the Late Jurassic of Svalbard
Authors: Angst Delphine , Buffetaut Eric , Tabouelle Jérôme , Tong Haiyan
Published: November 2010

An ichthyosaur skull discovered in the Upper Jurassic of Svalbard is described for the first time. It is mainly characterised by a relatively long snout and numerous small teeth, which are characters also found in the Late Jurassic ichthyosaur genera Brachypterygius and Aegirosaurus. On the basis of more detailed comparisons, the specimen is referred to Brachypterygius. This find extends the geographical distribution of that ichthyosaur genus, hitherto known from England, to the high latitudes of the Late Jurassic, and suggests that ichthyosaurs could withstand relatively low water temperatures.
National, Transnational, and Hypernational Historiographies: New France Meets Early American History
Authors: Greer Allan
Published: November 2010

Abstract:

Have transnational currents (Atlantic, borderlands, continentalist) in the history of colonial North America overcome the distortions long associated with a national framing of research on the early modern period? Have we left behind the tendency to read the political geography of the nineteenth century back into the history of the seventeenth and eighteenth centuries? Taking the example of writings on New France, a colonial formation that sprawled across large parts of what was to become Canada and the United States, this article argues that national historiographic traditions continue to exert a powerful influence. Even as they pursue their subject across modern borders, Canadian, Quebec and United States historians frequently view New France through the lens of their own respective national traditions. The recent upsurge of interest in New France on the part of Early Americanists is a welcome development, but its impact is somewhat vitiated by a tendency to retain a United States-centric intellectual agenda while annexing new territories and cultures to what remains a national intellectual enterprise. The article concludes with the suggestion that New France specialists situate their work more in a wider hemispheric context, one that includes comparative perspectives on Latin America and the Caribbean.
Catalysis: transition-state molecular recognition?
Authors: Williams Ian H
Published: November 2010

The key to understanding the fundamental processes of catalysis is the transition state (TS): indeed, catalysis is a transition-state molecular recognition event. Practical objectives, such as the design of TS analogues as potential drugs, or the design of synthetic catalysts (including catalytic antibodies), require prior knowledge of the TS structure to be mimicked. Examples, both old and new, of computational modelling studies are discussed, which illustrate this fundamental concept. It is shown that reactant binding is intrinsically inhibitory, and that attempts to design catalysts that focus simply upon attractive interactions in a binding site may fail. Free-energy changes along the reaction coordinate for SN2 methyl transfer catalysed by the enzyme catechol-O-methyl transferase are described and compared with those for a model reaction in water, as computed by hybrid quantum-mechanical/molecular-mechanical molecular dynamics simulations. The case is discussed of molecular recognition in a xylanase enzyme that stabilises its sugar substrate in a (normally unfavourable) boat conformation and in which a single-atom mutation affects the free-energy of activation dramatically.
β-Hydroxy carbocation intermediates in solvolyses of di- and tetra-hydronaphthalene substrates
Authors: Kudavalli Jaya S , More O'Ferrall Rory A
Published: November 2010

Solvolysis of trichloroacetate esters of 2-methoxy-1,2-dihydro-1-naphthols shows a remarkably large difference in rates between the cis and trans isomers, kcis/ktrans = 1800 in aqueous acetonitrile. This mirrors the behaviour of the acid-catalysed dehydration of cis- and trans-naphthalene-1,2-dihydrodiols to form 2-naphthol, for which kcis/ktrans = 440, but contrasts with that for solvolysis of tetrahydronaphthalene substrates, 1-chloro-2-hydroxy-1,2,3,4-tetrahydronaphthalenes, for which kcis/ktrans = 0.5. Evidence is presented showing that the trans isomer of the dihydro substrates reacts unusually slowly rather than the cis isomer unusually rapidly. Comparison of rates of solvolysis of 1-chloro-1,2,3,4-tetrahydronaphthalene and the corresponding (cis) substrate with a 2-hydroxy group indicates that a β-OH slows the reaction by nearly 2000-fold, which represents a typical inductive effect characteristic also of cis-dihydrodiol substrates. The slow reaction of the trans-dihydrodiol substrate is consistent with initial formation of a β-hydroxynaphthalenium carbocation with a conformation in which a C–OH occupies an axial position β to the carbocation centre preventing stabilisation of the carbocation by C–H hyperconjugation, which would occur in the conformation initially formed from the cis isomer. It is suggested that C–H hyperconjugation is particularly pronounced for a β-hydroxynaphthalenium ion intermediate because the stability of its no-bond resonance structure reflects the presence of an aromatic naphthol structure.
Flagellin as an Adjuvant: Cellular Mechanisms and Potential
Authors: Mizel Steven B. , Bates John T.
Published: November 2010

Flagellin is a potent activator of a broad range of cell types involved in innate and adaptive immunity. An increasing number of studies have demonstrated the effectiveness of flagellin as an adjuvant, as well as its ability to promote cytokine production by a range of innate cell types, trigger a generalized recruitment of T and B lymphocytes to secondary lymphoid sites, and activate TLR5+CD11c+ cells and T lymphocytes in a manner that is distinct from cognate Ag recognition. The plasticity of flagellin has allowed for the generation of a range of flagellin–Ag fusion proteins that have proven to be effective vaccines in animal models. This review summarizes the state of our current understanding of the adjuvant effect of flagellin and addresses important areas of current and future research interest.
Emission and dry deposition of accumulation mode particles in the Amazon Basin
Authors: Ahlm L. , Krejci R. , Nilsson E. D. , Mårtensson E. M. , Vogt M. , Artaxo P.
Published: November 2010

Abstract. Size-resolved vertical aerosol number fluxes of particles in the diameter range 0.25–2.5 μm were measured with the eddy covariance method from a 53 m high tower over the Amazon rain forest, 60 km NNW of Manaus, Brazil. This study focuses on data measured during the relatively clean wet season, but a shorter measurement period from the more polluted dry season is used as a comparison. Size-resolved net particle fluxes of the five lowest size bins, representing 0.25–0.45 μm in diameter, were in general dominated by deposition in more or less all wind sectors in the wet season. This is an indication that the source of primary biogenic aerosol particles may be small in this particle size range. Transfer velocities within this particle size range were observed to increase linearly with increasing friction velocity and increasing particle diameter. In the diameter range 0.5–2.5 μm, vertical particle fluxes were highly dependent on wind direction. In wind sectors where anthropogenic influence was low, net upward fluxes were observed. However, in wind sectors associated with higher anthropogenic influence, deposition fluxes dominated. The net upward fluxes were interpreted as a result of primary biogenic aerosol emission, but deposition of anthropogenic particles seems to have masked this emission in wind sectors with higher anthropogenic influence. The net emission fluxes were at maximum in the afternoon when the mixed layer is well developed, and were best correlated with horizontal wind speed according to the equation log10 F=0.48 · U+2.21 where F is the net emission number flux of 0.5–2.5 μm particles [m−2 s−1] and U is the horizontal wind speed [ms−1] at the top of the tower.
Abiotic and biogeochemical signals derived from the seasonal cycles of tropospheric nitrous oxide
Authors: Nevison C. D. , Dlugokencky E. , Dutton G. , Elkins J. W. , Fraser P. , Hall B. , Krummel P. B. , Langenfelds R. L. , Prinn R. G. , Steele L. P. , Weiss R. F.
Published: November 2010

Abstract. Seasonal cycles in the mixing ratios of tropospheric nitrous oxide (N2O) are derived by detrending long-term measurements made at sites across four global surface monitoring networks. These cycles are examined for physical and biogeochemical signals. The detrended monthly data display large interannual variability, which at some sites challenges the concept of a "mean" seasonal cycle. The interannual variability in the seasonal cycle is not always correlated among networks that share common sites. In the Northern Hemisphere, correlations between detrended N2O seasonal minima and polar winter lower stratospheric temperature provide compelling evidence for a stratospheric influence, which varies in strength from year to year and can explain much of the interannual variability in the surface seasonal cycle. Even at sites where a strong, competing, regional N2O source exists, such as from coastal upwelling at Trinidad Head, California, the stratospheric influence must be understood in order to interpret the biogeochemical signal in monthly mean data. In the Southern Hemisphere, detrended surface N2O monthly means are correlated with polar lower stratospheric temperature in months preceding the N2O minimum, suggesting a coherent stratospheric influence in that hemisphere as well. A decomposition of the N2O seasonal cycle in the extratropical Southern Hemisphere suggests that ventilation of deep ocean water (microbially enriched in N2O) and the stratospheric influx make similar contributions in phasing, and may be difficult to disentangle. In addition, there is a thermal signal in N2O due to seasonal ingassing and outgassing of cooling and warming surface waters that is out of phase and thus competes with the stratospheric and ventilation signals. All the seasonal signals discussed above are subtle and are generally better quantified in high-frequency in situ data than in data from weekly flask samples, especially in the Northern Hemisphere. The importance of abiotic influences (thermal, stratospheric influx, and tropospheric transport) on N2O seasonal cycles suggests that, at many sites, surface N2O mixing ratio data by themselves are unlikely to provide information about seasonality in surface sources (e.g., for atmospheric inversions), but may be more powerful if combined with complementary data such as CFC-12 mixing ratios or N2O isotopes.
Sensitivity of mesoscale model urban boundary layer meteorology to urban morphology
Authors: Flagg D. D. , Taylor P. A.
Published: November 2010

Abstract. Mesoscale modeling of the urban boundary layer requires careful parameterization of the surface due to its heterogeneous morphology. Model estimated meteorological quantities, including the surface energy budget and canopy layer variables, will respond accordingly to the scale of representation. This study examines the sensitivity of the surface energy balance, canopy layer and boundary layer meteorology to the scale of urban surface representation in a real urban area (Detroit-Windsor (USA-Canada)) during several dry, cloud-free summer periods. The model used is the Weather Research and Forecasting (WRF) model with its coupled single-layer urban canopy model. Some model verification is presented using measurements from the Border Air Quality and Meteorology Study (BAQS-Met) 2007 field campaign and additional sources. Case studies span from "neighborhood" (10 s ~ 30 m) to very coarse (120 s ~ 3.7 km) resolution. Small changes in scale can affect the classification of the surface, affecting both the local and grid-average meteorology. Results indicate high sensitivity in turbulent latent heat flux from the natural surface and sensible heat flux from the urban canopy. Small scale change is also shown to delay timing of a lake-breeze front passage and can affect the timing of local transition in static stability.
The global ocean circulation on a retrograde rotating earth
Authors: Kamphuis V. , Huisman S. E. , Dijkstra H. A.
Published: November 2010

Abstract. To understand the three-dimensional ocean circulation patterns that have occurred in past continental geometries, it is crucial to study the role of the present-day continental geometry and surface (wind stress and buoyancy) forcing on the present-day global ocean circulation. This circulation, often referred to as the Conveyor state, is characterized by an Atlantic Meridional Overturning Circulation (MOC) with deep water formation at northern latitudes and the absence of such deep water formation in the North Pacific. This MOC asymmetry is often attributed to the difference in surface freshwater flux: the North Atlantic is a basin with net evaporation, while the North Pacific receives net precipitation. This issue is revisited in this paper by considering the global ocean circulation on a retrograde rotating earth, computing an equilibrium state of the coupled atmosphere-ocean-land surface-sea ice model CCSM3. The Atlantic-Pacific asymmetry in surface freshwater flux is indeed reversed but the ocean circulation pattern is not an Inverse Conveyor state (with deep water formation in the North Pacific) as there is strong and highly variable deep water formation in the North Atlantic. Using a fully-implicit, global ocean-only model also the stability properties of the Atlantic MOC on a retrograde rotating earth are investigated, showing a similar regime of multiple equilibria as in the present-day case. These results demonstrate that the present-day asymmetry in surface freshwater flux is not a crucial factor for the Atlantic-Pacific asymmetry in the global MOC.
Real‐time aircraft radar simulator for a navy training system
Authors: D'Amato J. P. , García Bauza C. , Boroni G. , Vénere M.
Published: November 2010

A real‐time aircraft radar simulation applied in naval training is presented. The implemented algorithm works on a 3D synthesized environment, described by large sets of polygons—a typical scene can have a million of triangles—and the lobe is discretized with a cluster of rays. The radar display is recreated solving fast ray–polygon intersections (a variation of Ray‐Shooting), and mapping them on the screen. This work proposes a new polygonal simplification method and a geometric classification algorithm in order to solve the intersections efficiently. This methodology leads to high fidelity images and real‐time radar simulation, which operates at the specified 15 revolutions per minute rate. The results were tested with trained aircraft pilots. © 2010 Wiley Periodicals, Inc. Comput Appl Eng Educ 21: 606–613, 2013
Fate of retinoic acid–activated embryonic cell lineages
Authors: Dollé Pascal , Fraulob Valérie , Gallego‐Llamas Jabier , Vermot Julien , Niederreither Karen
Published: November 2010

Retinoic acid (RA), a vitamin A derivative, is synthesized by specific cell populations and acts as a diffusible embryonic signal activating ligand‐inducible transcription factors, the RA receptors (RARs). RA‐activatable transgenic systems have revealed many discrete, transient sites of RA action during development. However, there has been no attempt to permanently label the RA‐activated cell lineages during mouse ontogenesis. We describe the characterization of a RA‐activatable Cre transgene, which through crosses with a conditional reporter strain (the ROSA26R lacZ reporter), leads to a stable labeling of the cell populations experiencing RA signaling during embryogenesis. RA response‐element (RARE) ‐driven Cre activity mimics at early stages the known activity of the corresponding RARE‐lacZ transgene (Rossant et al.,1991). Stable labeling of the Cre‐excised cell populations allows to trace the distribution of the RA‐activated cell lineages at later stages. These are described in relationship with current models of RA activity in various developmental systems, including the embryonic caudal region, limb buds, hindbrain, sensory organs, and heart. Developmental Dynamics 239:3260–3274, 2010. © 2010 Wiley‐Liss, Inc.
Synthesis of Fluorescence‐Labelled Glycosidic Prodrugs Based on the Cytotoxic Antibiotic Duocarmycin
Authors: Tietze Lutz F. , Behrendt Frank , Major Felix , Krewer Birgit , von Hof J. Marian
Published: November 2010

The synthesis of the glycosidic prodrugs (1S)‐30a, (1S,10R)‐30b and (1S,10R)‐32 labelled with different fluorescence dyes at different positions at the aromatic A‐ring in 2 is described; the compounds are structurally based on the cytotoxic antibiotic duocarmycin SA. For binding, the amino compounds (1S)‐3a and (1S,10R)‐3b were treated with the commercially available succinimides of the dyes 5‐SFX (29) and D10162 (31), respectively.
Human aspect in reengineering projects—Conclusions from industrial application
Authors: Pawlewski Paweł , Cempel Witold A.
Published: November 2010

The aim of this article is to present the methodology of reengineering projects, taking into consideration the systemic and systematic aspect of human factors so that it constitutes a crucial component of the methodology. The idea of considering this factor stems from investigations connected with the reengineering project that was implemented in a factory producing ship engines. On the one hand, the research resulted in identifying a gap in the reengineering methodology (i.e., not taking simulation into account). On the other hand, an idea appeared to use the simulation as a factor that can prevent or reduce unfavorable reactions and opposition from workers reluctant to accept changes that are an unavoidable effect of a reengineering project. This article presents a literature review on change management, reengineering methodologies, and simulation tools (putting special emphasis on Petri nets). The case study of the implemented project consists of two stages. At the first stage, the methodology of the project was defined, based on the simulation with the use of Petri nets; next, the project was implemented, and, as a conclusion, the need for additional investigations was determined. At the second stage, the scope of the additional research was determined based on Rapid Re methodology; then the investigations were conducted and the suggestions for specific changes in the investigated process were defined. The article ends with general conclusions and suggests changes in the methodology (providing Rapid Re as an example). The authors suggest introducing mechanisms that take into account the human factor based on the simulation technique. The proposed changes give a solid foundation for developing a precise solution for a company, and, as such, they will be the subject of further investigations by the authors. © 2010 Wiley Periodicals, Inc.
A NEW EXPLANATION FOR THE REPRODUCTIVE WOES AND MIDLIFE DECLINE OF HENRY VIII
Authors: WHITLEY CATRINA BANKS , KRAMER KYRA
Published: November 2010

Henry VIII's first two wives experienced multiple pregnancies culminating in late-term miscarriage, stillbirth, or neonatal mortality. After his fortieth birthday, the king's mental and physical health underwent rapid deterioration. In this article, we argue that both his reproductive troubles and his midlife pathologies can be explained if Henry VIII were positive for the Kell blood group. A Kell negative woman who has multiple pregnancies with a Kell positive male will suffer repeated miscarriages and death of Kell positive foetuses and term infants that occur subsequent to the first Kell positive pregnancy. This pattern is consistent with the pregnancies of Katherine of Aragon and Anne Boleyn. Additionally, Henry VIII may have suffered from McLeod syndrome, a genetic disorder of the Kell blood group system, which is a condition that causes physical and mental impairment consistent with his ailments.
Local differences in habitat selection by Great BustardsOtis tardain changing agricultural landscapes: implications for farmland bird conservation
Authors: LÓPEZ-JAMAR JUAN , CASAS FABIÁN , DÍAZ MARIO , MORALES MANUEL B.
Published: November 2010

Local changes in land use can influence patterns of habitat selection by farmland birds, thus biasing predictions of population responses to land use changes based on wildlife-habitat or niche modelling. This study, based in arable farmland in south-central Spain, determined whether habitat selection (use of agricultural habitats and the distance to roads, tracks and buildings) by Great BustardsOtis tardavaried between two nearby areas with differing land uses. The western sector has experienced a process of land abandonment and infrastructure development linked to an airport project that started in 1998 and finished in 2009, while the eastern sector maintains extensive dry farmland systems. Great Bustards avoided ploughed fields and selected short- and long-term fallows. Selection of fallows was more intensive in the sector suffering recent land-use changes, where these substrates were more abundant. Great Bustards were distributed further from roads, paths and buildings than would be expected if individual birds selected habitats at random. Avoidance of infrastructure was strongest in the area suffering recent land-use changes. Local patterns of habitat selection seemed to change in relation to agricultural abandonment and infrastructure development. Consequently, conservation measures based on knowledge of broad patterns of habitat use and selection such as agri-environmental schemes may fail to ensure steppe bird conservation locally if such local effects are overlooked. Specifically, schemes should include landscape-scale restrictions on the development and use of infrastructure (roads, tracks and buildings). Analyses of the patterns and causes of local and regional changes in habitat selection are essential to conserve populations of endangered farmland birds.
Europa Lander Mission: A Challenge to Find Traces of Alien Life
Authors: Zelenyi Lev , Korablev Oleg , Vorobyova Elena , Martynov Maxim , Akim Efraim L. , Zakahrov Alexander
Published: November 2010

An international effort dedicated to science exploration of Jupiter system planned by ESA and NASA in the beginning of next decade includes in-depth science investigation of Europa. In parallel to EJSM (Europa-Jupiter System Mission) Russian Space Agency and the academy of Science plan Laplace-Europa Lander mission, which will include the small telecommunication and science orbiter and the surface element: Europa Lander. In-situ methods on the lander provide the only direct possibility to assess environmental conditions, and to perform the search for signatures of life. A critical advantage of such in situ analysis is the possibility to enhance concentration and detection limits and to provide ground truth for orbital measurements. The science mission of the lander is biological, geophysical, chemical, and environmental characterizations of the Europa surface. Remote investigations from the orbit around Europa would not be sufficient to address fully the astrobiology, geodesy, and geology goals. The science objectives of the planned mission, the synergy between the Europa Lander and EJSM mission elements, and a brief description of the Laplace-Europa Lander mission are presented.
A rotator for single-crystal neutron diffraction at high pressure
Authors: Fang J. , Bull C. L. , Hamidov H. , Loveday J. S. , Gutmann M. J. , Nelmes R. J. , Kamenev K. V.
Published: November 2010

We present a modified Paris–Edinburgh press which allows rotation of the anvils and the sample under applied load. The device is designed to overcome the problem of having large segments of reciprocal space obscured by the tie rods of the press during single-crystal neutron-scattering experiments. The modified press features custom designed hydraulic bearings and provides controls for precision rotation and positioning. The advantages of using the device for increasing the number of measurable reflections are illustrated with the results of neutron-diffraction experiments on a single crystal of germanium rotated under a load of 70 tonnes.
Homogeneous nucleation and growth in simple fluids. II. Scaling behavior, instabilities, and the (n,v) order parameter
Authors: Uline Mark J. , Torabi Korosh , Corti David S.
Published: November 2010

The free energy of forming a droplet and a bubble with a given number of particles n inside a volume v within the pure component Lennard-Jones supercooled vapor and superheated liquid, respectively, is further explored using density-functional theory. Certain key aspects of the free energy surface for bubble formation, such as the radius of the bubble at a stability limit, are found to scale in a nearly temperature independent manner when plotted versus a parameter that quantifies the location of the given state point in the metastable region. The corresponding work at this stability limit exhibits scaling for small values of n, but shows a strong temperature dependence for large n. No aspect of the free energy surface for droplet formation shows scaling over the full range of metastability conditions, including the work of forming the critical droplet and the radius of a droplet at its stability limit. Hence, there is no “universal” surface for embryo formation in metastable fluids. We also generate by thermodynamic arguments alone droplet and bubble trajectories along the corresponding free energy surfaces that avoid by construction the locus of instabilities, which match quite well the results obtained from other approaches. We also discuss in greater detail the use of the (n,v) order parameter within an equilibrium-based description of embryo formation, focusing on why the density profile of the embryo is found to be discontinuous at the embryo surface and why stability limits are expected to develop at certain bubble radii.
Nonadiabatic quantum reactive scattering of the OH(A Σ2+)+D2
Authors: Zhang Pei-Yu , Lu Rui-Feng , Chu Tian-Shu , Han Ke-Li
Published: November 2010

The seams of conical intersection exist between the ground (1 A2′) and the first-excited (2 A2′) electronic potential energy surfaces (PESs) of OH(A Σ2+,X Π2)+H2 system. This intersection induces the nonadiabatic quenching of OH(A Σ2+) by D2. We present nonadiabatic quantum dynamics study for OH(A Σ2+)+D2 on new five-dimensional coplanar PESs. The ab initio calculations of PESs are based on multireference configuration interaction (MRCI)/aug-cc-pVQZ level. A back-propagation neural network is utilized to fit the PESs and nonadiabatic coupling. High degrees of rotational excitation of quenched OH(X Π2) products are found in nonreactive quenching channel, and the quenched D2 products are vibrationally excited up to quantum number v2′=8. The theoretical results of nonadiabatic time-dependent wave-packet calculation are in good agreement with the existing experimental data.
Monte Carlo study of kink effect in isolated-gate InAs/AlSb high electron mobility transistors
Authors: Vasallo B. G. , Rodilla H. , González T. , Moschetti G. , Grahn J. , Mateos J.
Published: November 2010

A semiclassical two-dimensional ensemble Monte Carlo simulator is used to perform a physical analysis of the kink effect in InAs/AlSb high electron mobility transistors (HEMTs). Kink effect, this is, an anomalous increase in the drain current ID when increasing the drain-to-source voltage VDS, leads to a reduction in the gain and a rise in the level of noise, thus limiting the utility of these devices for microwave applications. Due to the small band gap of InAs, InAs/AlSb HEMTs are very susceptible to suffer from impact ionization processes, with the subsequent hole transport through the structure, both implicated in the kink effect. The results indicate that, when VDS is high enough for the onset of impact ionization, holes thus generated tend to pile up in the buffer (at the gate-drain side) due to the valence-band energy barrier between the buffer and the channel. Due to this accumulation of positive charge the channel is further opened and ID increases, leading to the kink effect in the I-V characteristics and eventually to the device electrical breakdown. The understanding of this phenomenon provides useful information for the development of kink-effect-free InAs/AlSb HEMTs.