bluuebunny/crossref_metadata_2025 huggingface dataset:
Contribution of Saharan dust on radionuclide aerosol activity levels in Europe? The 21–22 February 2004 case study
Authors: Menut Laurent , Masson Olivier , Bessagnet Bertrand
Published: August 2009

In February 2004, a spectacular dust event was observed in the south of France. Associated with huge particulate matter deposition, unusual 137Cs concentrations were found in samples. Using the transport model CHIMERE‐DUST, we first show that these dust aerosols came from North Africa. More precisely, the question is whether this sudden increase of measured 137Cs concentrations was due to a huge amount of dust over a large region (with an usual radionuclide content) or due to an import of more concentrated air masses over a limited area. This question is connected to the open debate about the contribution of 137Cs concentrations in Europe from “Gerboise” sites, where former French nuclear tests in the 1960s were performed. With the model in scenario mode, this study attempts to track down 137Cs concentrations recorded in the south of France. To quantify the origin and percentage of dust originating from North Africa to the south of France, three simulations are performed: (1) with the complete dust emissions inventory of Africa, (2) with only emissions in the eastern Maghreb, and (3) only considering the Gerboise sites. It is showed that the majority (80%) of the dust was coming from eastern Maghreb, but only 0.7% of the African emissions were from Gerboise, leading to 1–5% of the concentrations recorded in the south of France for the day of the peak.
Development of Incentives for Data Sharing in Ecology, Evolution, and Organismal Biology
Authors: Duke Clifford
Published: August 2009

Ready access to data is a key concern in both basic research and problem-solving in the biological sciences, as the scale and scope of the questions that researchers ask expand, and as global problems demand data collected from around the world. With a grant from the National Science Foundation, from 2004 through 2009, the Ecological Society of America (ESA) has led a series of five workshops on data sharing, to help the ecology, evolution, and organismal biology communities find common ground on how to make data more readily discoverable and accessible in their own disciplines. The most recent of these focused in the development of incentives for data sharing, both at the individual and organizational level. This presentation will summarize the workshop recommendations, with a focus on preservation, curation, and access to data; access to analytical and visualization tools; and the need to make data archiving simple and routine. The roles of funders and publishers of research are also key and will be highlighted.

Background/Question/Methods

Ready access to data is a key concern in both basic research and problem-solving in the biological sciences, as the scale and scope of the questions that researchers ask expand, and as global problems demand data collected from around the world. With a grant from the National Science Foundation, from 2004 through 2009, the Ecological Society of America (ESA) has led a series of five workshops on data sharing, to help the ecology, evolution, and organismal biology communities find common ground on how to make data more readily discoverable and accessible in their own disciplines. The most recent of these focused in the development of incentives for data sharing, both at the individual and organizational level.

Results/Conclusions

This presentation will summarize the workshop recommendations, with a focus on preservation, curation, and access to data; access to analytical and visualization tools; and the need to make data archiving simple and routine. The roles of funders and publishers of research are also key and will be highlighted.
Status and habitat requirements of Physaria thamnophila, an endangered species of Tamaulipan thornscrub
Authors: Fowler Norma , Price Dana , Best Christopher , Hempel Alice
Published: August 2009

Physaria (Lesquerella) thamnophila (Brassicaceae; henceforth Physaria) is an endangered herbaceous perennial plant of remnant patches of Tamaulipan thornscrub near the southern Texas border. Six years of censuses of four populations of Physaria were analyzed. Quantitative data were collected to describe the plant community in the four sites. There was no overall trend in population size, but fluctuations in observed numbers of plants among years were extremely large: a single census cannot provide a reliable assessment of a population of this species. Seedling numbers were positively related with shrub canopy cover. However, there were many more Physaria plants in the brush-cleared portion of one site than in its uncleared portion. Seedling survival may be facilitated by anything that reduces movement of the highly erodible soils of these sites.
C-terminal sequences of hsp70 and hsp90 as non-specific anchors for tetratricopeptide repeat (TPR) proteins
Authors: Ramsey Andrew J. , Russell Lance C. , Chinkers Michael
Published: August 2009

Steroid-hormone-receptor maturation is a multi-step process that involves several TPR (tetratricopeptide repeat) proteins that bind to the maturation complex via the C-termini of hsp70 (heat-shock protein 70) and hsp90 (heat-shock protein 90). We produced a random T7 peptide library to investigate the roles played by the C-termini of the two heat-shock proteins in the TPR–hsp interactions. Surprisingly, phages with the MEEVD sequence, found at the C-terminus of hsp90, were not recovered from our biopanning experiments. However, two groups of phages were isolated that bound relatively tightly to HsPP5 (Homo sapiens protein phosphatase 5) TPR. Multiple copies of phages with a C-terminal sequence of LFG were isolated. These phages bound specifically to the TPR domain of HsPP5, although mutation studies produced no evidence that they bound to the domain's hsp90-binding groove. However, the most abundant family obtained in the initial screen had an aspartate residue at the C-terminus. Two members of this family with a C-terminal sequence of VD appeared to bind with approximately the same affinity as the hsp90 C-12 control. A second generation pseudo-random phage library produced a large number of phages with an LD C-terminus. These sequences acted as hsp70 analogues and had relatively low affinities for hsp90-specific TPR domains. Unfortunately, we failed to identify residues near hsp90's C-terminus that impart binding specificity to individual hsp90–TPR interactions. The results suggest that the C-terminal sequences of hsp70 and hsp90 act primarily as non-specific anchors for TPR proteins.
Binding of cyclic nucleotides to phosphodiesterase 10A and 11A GAF domains does not stimulate catalytic activity
Authors: Matthiesen Karina , Nielsen Jacob
Published: August 2009

To date eleven human PDE (3′,5′-cyclic nucleotide phosphodiesterase) families have been identified. Of these, five families contain non-catalytic tandem GAF (cGMP-specific and -stimulated phosphodiesterases, Anabaenaadenylate cyclases and Escherichia coliFhlA) domains, GAFa and GAFb, in the N-terminal part of the enzyme. For PDE2A, PDE5A and PDE6 the GAF domains have been shown to bind cGMP with high affinity. For PDE2A and PDE5A this ligand binding has been shown to stimulate the catalytic activity of the enzyme. PDE10A and PDE11A are the two most recently described PDEs and it has been suggested that their GAF domains bind to cAMP and cGMP respectively. We have developed a scintillation proximity-based assay to directly measure cyclic nucleotide binding to the PDE2A, PDE10A and PDE11A GAF domains, and in the present study we demonstrate binding of cyclic nucleotides to the PDE10A and PDE11A GAF domains. We show that these non-catalytic sites bind cAMP and cGMP respectively with much higher affinity than has previously been suggested using indirect assessment of the interaction. The GAFb domain of PDE10A binds cAMP with a Kd of 48 nM and the GAFa domain of PDE11A binds cGMP with a Kd of 110 nM. The effect of cyclic nucleotides binding to the GAF domains on the enzyme activity was investigated through the use of modified cyclic nucleotides. In contrast with other GAF domain-containing PDEs, and with what has previously been predicted, ligand binding to the GAF domains of PDE10A and PDE11A does not stimulate catalytic activity.
Bremsstrahlung and Kα fluorescence measurements for inferring conversion efficiencies into fast ignition relevant hot electrons
Authors: Chen C. D. , Patel P. K. , Hey D. S. , Mackinnon A. J. , Key M. H. , Akli K. U. , Bartal T. , Beg F. N. , Chawla S. , Chen H. , Freeman R. R. , Higginson D. P. , Link A. , Ma T. Y. , MacPhee A. G. , Stephens R. B. , Van Woerkom L. D. , Westover B. , Porkolab M.
Published: August 2009

The Bremsstrahlung and K-shell emission from 1×1×1 mm3 planar targets irradiated by a short-pulse 3×1018–8×1019 W/cm2 laser were measured. The Bremsstrahlung was measured using a filter stack spectrometer with spectral discrimination up to 500 keV. K-shell emission was measured using a single photon counting charge coupled device. From Monte Carlo modeling of the target emission, conversion efficiencies into 1–3 MeV electrons of 3%–12%, representing 20%–40% total conversion efficiencies, were inferred for intensities up to 8×1019 W/cm2. Comparisons to scaling laws using synthetic energy spectra generated from the intensity distribution of the focal spot imply slope temperatures less than the ponderomotive potential of the laser. Resistive transport effects may result in potentials of a few hundred kV in the first few tens of microns in the target. This would lead to higher total conversion efficiencies than inferred from Monte Carlo modeling but lower conversion efficiencies into 1–3 MeV electrons.
Dynamic communities in multichannel data: An application to the foreign exchange market during the 2007–2008 credit crisis
Authors: Fenn Daniel J. , Porter Mason A. , McDonald Mark , Williams Stacy , Johnson Neil F. , Jones Nick S.
Published: August 2009

We study the cluster dynamics of multichannel (multivariate) time series by representing their correlations as time-dependent networks and investigating the evolution of network communities. We employ a node-centric approach that allows us to track the effects of the community evolution on the functional roles of individual nodes without having to track entire communities. As an example, we consider a foreign exchange market network in which each node represents an exchange rate and each edge represents a time-dependent correlation between the rates. We study the period 2005–2008, which includes the recent credit and liquidity crisis. Using community detection, we find that exchange rates that are strongly attached to their community are persistently grouped with the same set of rates, whereas exchange rates that are important for the transfer of information tend to be positioned on the edges of communities. Our analysis successfully uncovers major trading changes that occurred in the market during the credit crisis.
Re-entrance phase and excited metastable electronic spin states in one-dimensional spin crossover compounds explained by atom-phonon coupling model
Authors: Rotaru Aurelian , Linares Jorge , Mordelet Sebastien , Stancu Alexandru , Nasser Jamil
Published: August 2009

An unusual behavior of the disappearance and the reappearance of the hysteresis loop of the spin crossover compounds under external pressure was observed experimentally by Garcia et al. [Hyperfine Interact. 139/140, 543 (2002)] and modeled within the framework of the “atom-phonon coupling” model. In this contribution we explain the evolution of the hysteresis width versus the applied pressure. Using the same model, we also show the existence of stable as well as metastable and unstable states at very low temperatures. These excited metastable electronic spin states at low temperature can be associated to the “out of equilibrium” states in the light-induced electronic spin state trapping.
One-dimensional carrier localization and effective quantum wire behavior in two-dimensional quantum wedges
Authors: Riyopoulos S. , Moustakas T. D.
Published: August 2009

It is shown that quantum wedges (QWGs), i.e., ridges formed between intersecting plane quantum wells (QWs), cause carrier wave function localization in one dimension. In the absence of polarization fields only the fundamental mode is localized. When the inherent in GaN polarization is included many lower modes become confined. In QWGs, additional confinement of the wave function from the polarization field component along the QW causes blueshifting of the confined mode energy, as opposed to the redshifting induced by the transverse field component in straight QWs. The emission localization and blueshift agrees with experimental photoluminescence observations in QWs deposited on textured GaN. Electrostatic shielding of the parallel polar potential by free carriers leads to localized band bending at the wedges, instead of uniform band tilting, inducing tighter lateral carrier confinement. Thus the ridges formed by intersecting QWs behave as a network of quantum wires. Since electrons and holes are confined in opposite polarity wedges, separated by a QW length, direct recombination between QWG-trapped electrons and holes is unlikely; instead radiative emission at the wedges involves recombination between trapped electrons—“passing” holes and vice versa. A simplified analytical theory is introduced to obtain the energy levels and the transition probabilities via overlap integrals. The passing-trapped emission rates are comparable to those for emission in flat QWs, and the blueshift in wavelength is in good agreement with the observed values.
Effects of oxygen depletion on photoinduced and transport properties of thin films of charge-ordered manganites
Authors: Smolyaninova V. N. , Yong G. , Kolagani Rajeswari M. , Karki K. , Hofmann B.
Published: August 2009

In this paper, we report a study of conductive and photoinduced properties of charge-ordered Bi0.4Ca0.6MnO3 thin films with different oxygen contents. The oxygen content of the films was varied following different annealing or deposition protocols. Change in film’s resistivity during annealing reflects oxygen dynamics at high temperatures. It was found that oxygen-deficient films exhibit a significant increase in the photoinduced resistivity changes and the lifetime of photoinduced conductive phase. Possible origin of this effect is discussed.
Amorphization of crystalline Si due to heavy and light ion irradiation
Authors: Edmondson P. D. , Riley D. J. , Birtcher R. C. , Donnelly S. E.
Published: August 2009

The formation of amorphous silicon in crystalline silicon by bombardment with light (Si) and heavy (Xe) ions has been investigated by transmission electron microscopy with in situ ion irradiation. Experiments have been carried out at room temperature and low temperature (50K) and the results are compared to a simple numerical model for amorphization. The results indicate that the amorphization mechanisms for both irradiations are heterogeneous in nature and that numerous overlaps of the collision cascade are generally required to render the crystal amorphous. Following from this, the nature of the material within the confines of collision cascades will be discussed and it will be shown that the individual cascade volume is not necessarily amorphous as previously described in the scientific literature but contains varying degrees of damage depending on the energy deposited within the cascade.
Nekhoroshev theorem for the periodic Toda lattice
Authors: Henrici Andreas , Kappeler Thomas
Published: August 2009

The periodic Toda lattice with N sites is globally symplectomorphic to a two parameter family of N−1 coupled harmonic oscillators. The action variables fill out the whole positive quadrant of RN−1. We prove that in the interior of the positive quadrant as well as in a neighborhood of the origin, the Toda Hamiltonian is strictly convex and therefore Nekhoroshev’s theorem applies on (almost) all parts of phase space (2000 Mathematics Subject Classification: 37J35, 37J40, 70H06).
Determination of three-dimensional orientations of ferroelectric single crystals by an improved rotating orientation x-ray diffraction method
Authors: Li Fei , Jin Li , Xu Zhuo , Guo Zhenqi
Published: August 2009

X-ray diffraction (XRD) techniques are widely used in determining crystallographic orientations. In this paper we describe a two-step method to determine the three-dimensional orientations of ferroelectric single crystals based on an improved rotating orientations XRD method. This method could be readily carried out on standard x-ray laboratory equipment. Taking into account the geometric relationship in crystallography, we obtain an equation to find the expected crystallographic plane and simplify the determining process. The application of this method to LiNbO3 and xPb(Mg1/3Nb2/3)O3–(1−x)PbTiO3 ferroelectric single crystals demonstrates that it is a fast, flexible, and waste-free method for crystallographic orientation. Explanations of the scanning diffraction patterns and evaluation of the determining accuracy are presented. This method is also applicable to other nonferroelectric single crystal systems and would benefit the orientation-related issues.
Liquid-crystal phase transition by electron shower in a direct current complex plasma
Authors: Uchida Giichiro , Iizuka Satoru , Sato Noriyoshi
Published: August 2009

The Coulomb crystal of strongly coupled fine particles is formed by electron shower in a direct current discharge plasma, where the electron shower is injected from an auxiliary plasma which is situated below a main plasma. In case of electron shower injection, the phase transition of dust particles is controlled under the constant argon pressure. The characteristic properties of electron shower injection are discussed theoretically by using a simple collisional sheath model. The calculation analysis clearly shows that electron injection causes the change in charges on fine particles, resulting in a liquid-solid phase transition as in the experiment.
Linear stability analysis of gyrotactic plumes
Authors: Ghorai S. , Singh R.
Published: August 2009

Bioconvection occurs as the result of the collective behavior of many micro-organisms swimming in a fluid and is realized as patterns similar to those of thermal convection, which occur when a layer of fluid is heated from below. We consider the phenomenon of pattern formation due to gyrotaxis, an orientation mechanism which results from the balance of gravitational and viscous torques acting on bottom-heavy micro-organisms. Using the continuum model of Pedley et al. [“The growth of bioconvection patterns in a uniform suspension of gyrotactic micro-organisms,” J. Fluid Mech. 195, 223 (1988)], the linear stability of a gyrotactic plume (descending line of concentrated micro-organisms) is investigated. Linear stability analysis predicts that a plume is always unstable to both the varicose and meandering modes. The growth rates of these instability modes and their dependence on parameter values are investigated. Comparisons are made with the experimental and numerical results.
Nucleation tendency and crystallizing phase in silicate glasses: A structural aspect
Authors: Takahashi Yoshihiro , Masai Hirokazu , Fujiwara Takumi
Published: August 2009

We consider the relationship of nucleation tendency with crystallizing-phase structures in silicate glasses using glassy sanbornite (1BaO–2SiO2) that shows homogeneous nucleation resulting crystallization of Ba5Si8O21 and β-BaSi2O5 phases with a layered structure of a network modifier and a network former. This trend is also confirmed in other silicate glasses with homogeneous nucleation tendency, which has been assessed by Zanotto and other researchers. It is suggested that the structural dimension of the crystallizing phase governs the nucleation tendency in silicate glasses.
Self-supporting nanowire arrays templated in sacrificial branched porous anodic alumina for thermoelectric devices
Authors: Biswas Kalapi G. , El Matbouly Hatem , Rawat Vijay , Schroeder Jeremy L. , Sands Timothy D.
Published: August 2009

Templated synthesis of thermoelectric nanowires in porous anodic alumina (PAA) have potential for enhanced performance relative to bulk materials. A significant challenge is the template material, which can serve as a thermal shunt. In this work, an approach for creating a branched PAA template is described. The process utilizes localized self-heating to destabilize the planar anodization front, yielding branched and interconnected pores growing at a rate of 300 μm/h. The template is selectively etched after electrodeposition of desired materials, yielding self-supporting nanowire arrays with thicknesses up to about 300 μm, thereby eliminating the thermal shunt through the template.
Terahertz radiation detection by field effect transistor in magnetic field
Authors: Boubanga-Tombet S. , Sakowicz M. , Coquillat D. , Teppe F. , Knap W. , Dyakonov M. I. , Karpierz K. , Łusakowski J. , Grynberg M.
Published: August 2009

We report on terahertz radiation detection with InGaAs/InAlAs field effect transistors in quantizing magnetic field. The photovoltaic detection signal was investigated as a function of the gate voltage and magnetic field. Oscillations analogous to Shubnikov–de Haas oscillations as well as their strong enhancement at the cyclotron resonance were observed. The results are quantitatively described by a recent theory, showing that the detection is due to rectification of the terahertz radiation by plasma waves related nonlinearities in the gated part of the channel.
Anomalous amplitude dependence of the Shapiro steps
Authors: Tekić Jasmina , Hu Bambi
Published: August 2009

Amplitude dependence of the Shapiro steps is studied in the ac driven overdamped Frenkel–Kontorova model with deformable substrate potential. It was found that as potential gets deformed, appearance of large subharmonic steps strongly influence the properties of harmonic steps. In their amplitude dependence, different types of behavior have been classified and deviation from the well known Bessel-like oscillations has been observed. These phenomena may significantly influence stability and existence of interference effects in real systems.
Modelling the quasistatic and dynamical sensing response of Galfenol-based magnetostrictive devices
Authors: Weetman Philip , Akhras George
Published: August 2009

A computational model for the quasistatic and dynamical response of Galfenol based magnetostrictive devices in the sensing configuration is presented. The model calculates the fraction of magnetic moments oriented along the preferred orientations within the crystal as a function of time using a self-consistent rate equation technique. These magnetic moment fractions are then used to determine the total magnetization as a function of time. The model is compared to experiments for uniaxial, compressive, and quasistatic loading. Predictive calculations are presented for dynamical loading. Eddy currents and finite transition times lead to increasing hysteresis as the frequency increases.
Quasifree Mg–H thin films
Authors: Baldi A. , Palmisano V. , Gonzalez-Silveira M. , Pivak Y. , Slaman M. , Schreuders H. , Dam B. , Griessen R.
Published: August 2009

The thermodynamics of hydrogen absorption in Pd-capped Mg films are strongly dependent on the magnesium thickness. In the present work, we suppress such dependency by inserting a thin Ti layer between Mg and Pd. By means of optical measurements, we show that the surface energy contribution to the destabilization of MgH2 is negligible. The inserted Ti layer prevents Mg–Pd alloy formation at the Mg/Pd interface, leading to quasifree Mg films and enhancing the kinetics of hydrogen desorption. Our observations are important for the development of thin film devices.
Self-organization of engineered epithelial tubules by differential cellular motility
Authors: Mori Hidetoshi , Gjorevski Nikolce , Inman Jamie L. , Bissell Mina J. , Nelson Celeste M.
Published: August 2009

Patterning of developing tissues arises from a number of mechanisms, including cell shape change, cell proliferation, and cell sorting from differential cohesion or tension. Here, we reveal that differences in cell motility can also lead to cell sorting within tissues. Using mosaic engineered mammary epithelial tubules, we found that cells sorted depending on their expression level of the membrane-anchored collagenase matrix metalloproteinase (MMP)-14. These rearrangements were independent of the catalytic activity of MMP14 but absolutely required the hemopexin domain. We describe a signaling cascade downstream of MMP14 through Rho kinase that allows cells to sort within the model tissues. Cell speed and persistence time were enhanced by MMP14 expression, but only the latter motility parameter was required for sorting. These results indicate that differential directional persistence can give rise to patterns within model developing tissues.
Centromere repositioning in cucurbit species: Implication of the genomic impact from centromere activation and inactivation
Authors: Han Yonghua , Zhang Zhonghua , Liu Chunxia , Liu Jinhua , Huang Sanwen , Jiang Jiming , Jin Weiwei
Published: August 2009

The centromere of an eukaryotic chromosome can move to a new position during evolution, which may result in a major alteration of the chromosome morphology and karyotype. This centromere repositioning phenomenon has been extensively documented in mammalian species and was implicated to play an important role in mammalian genome evolution. Here we report a centromere repositioning event in plant species. Comparative fluorescence in situ hybridization mapping using common sets of fosmid clones between two pairs of cucumber (
Cucumis sativus
L.) and melon (
Cucumis melo
L.) chromosomes revealed changes in centromere positions during evolution. Pachytene chromosome analysis revealed that the current centromeres of all four cucumber and melon chromosomes are associated with distinct pericentromeric heterochromatin. Interestingly, inactivation of a centromere in the original centromeric region was associated with a loss or erosion of its affixed pericentromeric heterochromatin. Thus, both centromere activation and inactivation in cucurbit species were associated with a gain/loss of a large amount of pericentromeric heterochromatin.
Differential distribution of endoplasmic reticulum controls metabotropic signaling and plasticity at hippocampal synapses
Authors: Holbro Niklaus , Grunditz Åsa , Oertner Thomas G.
Published: August 2009

Synaptic plasticity is considered essential for learning and storage of new memories. Whether all synapses on a given neuron have the same ability to express long-term plasticity is not well understood. Synaptic microanatomy could affect the function of local signaling cascades and thus differentially regulate the potential for plasticity at individual synapses. Here, we investigate how the presence of endoplasmic reticulum (ER) in dendritic spines of CA1 pyramidal neurons affects postsynaptic signaling. We show that the ER is targeted selectively to large spines containing strong synapses. In ER-containing spines, we frequently observed synaptically triggered calcium release events of very large amplitudes. Low-frequency stimulation of these spines induced a permanent depression of synaptic potency that was independent of NMDA receptor activation and specific to the stimulated synapses. In contrast, no functional changes were induced in the majority of spines lacking ER. Both calcium release events and long-term depression depended on the activation of metabotropic glutamate receptors and inositol trisphosphate receptors. In summary, spine microanatomy is a reliable indicator for the presence of specific signaling cascades that govern plasticity on a micrometer scale.
Mapping accessible chromatin regions using Sono-Seq
Authors: Auerbach Raymond K. , Euskirchen Ghia , Rozowsky Joel , Lamarre-Vincent Nathan , Moqtaderi Zarmik , Lefrançois Philippe , Struhl Kevin , Gerstein Mark , Snyder Michael
Published: August 2009

Disruptions in local chromatin structure often indicate features of biological interest such as regulatory regions. We find that sonication of cross-linked chromatin, when combined with a size-selection step and massively parallel short-read sequencing, can be used as a method (Sono-Seq) to map locations of high chromatin accessibility in promoter regions. Sono-Seq sites frequently correspond to actively transcribed promoter regions, as evidenced by their co-association with RNA Polymerase II ChIP regions, transcription start sites, histone H3 lysine 4 trimethylation (H3K4me3) marks, and CpG islands; signals over other sites, such as those bound by the CTCF insulator, are also observed. The pattern of breakage by Sono-Seq overlaps with, but is distinct from, that observed for FAIRE and DNase I hypersensitive sites. Our results demonstrate that Sono-Seq can be a useful and simple method by which to map many local alterations in chromatin structure. Furthermore, our results provide insights into the mapping of binding sites by using ChIP–Seq experiments and the value of reference samples that should be used in such experiments.
The dynamics of deterrence
Authors: Kleiman Mark , Kilmer Beau
Published: August 2009

Because punishment is scarce, costly, and painful, optimal enforcement strategies will minimize the amount of actual punishment required to effectuate deterrence. If potential offenders are sufficiently deterrable, increasing the conditional probability of punishment (given violation) can reduce the amount of punishment actually inflicted, by “tipping” a situation from its high-violation equilibrium to its low-violation equilibrium. Compared to random or “equal opportunity” enforcement, dynamically concentrated sanctions can reduce the punishment level necessary to tip the system, especially if preceded by warnings. Game theory and some simple and robust Monte Carlo simulations demonstrate these results, which, in addition to their potential for reducing crime and incarceration, may have implications for both management and regulation.
Insulin crystallization depends on zinc transporter ZnT8 expression, but is not required for normal glucose homeostasis in mice
Authors: Lemaire K. , Ravier M. A. , Schraenen A. , Creemers J. W. M. , Van de Plas R. , Granvik M. , Van Lommel L. , Waelkens E. , Chimienti F. , Rutter G. A. , Gilon P. , Veld P. A. in't , Schuit F. C.
Published: August 2009

Zinc co-crystallizes with insulin in dense core secretory granules, but its role in insulin biosynthesis, storage and secretion is unknown. In this study we assessed the role of the zinc transporter ZnT8 using ZnT8-knockout (
ZnT8
−/−
) mice. Absence of ZnT8 expression caused loss of zinc release upon stimulation of exocytosis, but normal rates of insulin biosynthesis, normal insulin content and preserved glucose-induced insulin release. Ultrastructurally, mature dense core insulin granules were rare in
ZnT8
−/−
beta cells and were replaced by immature, pale insulin “progranules,” which were larger than in
ZnT8
+/+
islets. When mice were fed a control diet, glucose tolerance and insulin sensitivity were normal. However, after high-fat diet feeding, the
ZnT8
−/−
mice became glucose intolerant or diabetic, and islets became less responsive to glucose. Our data show that the ZnT8 transporter is essential for the formation of insulin crystals in beta cells, contributing to the packaging efficiency of stored insulin. Interaction between the
ZnT8
−/−
genotype and diet to induce diabetes is a model for further studies of the mechanism of disease of human ZNT8 gene mutations.
Identification and characterization of posttranslational modification-specific binding proteins in vivo by mammalian tethered catalysis
Authors: Spektor Tanya M. , Rice Judd C.
Published: August 2009

Increasing evidence indicates that an important consequence of protein posttranslational modification (PTM) is the creation of a high affinity binding site for the selective interaction with a PTM-specific binding protein (BP). This PTM-mediated interaction is typically required for downstream signaling propagation and corresponding biological responses. Because the vast majority of mammalian proteins contain PTMs, there is an immediate need to discover and characterize previously undescribed PTMBPs. To this end, we developed and validated an innovative in vivo approach called mammalian tethered catalysis (MTeC). By using methylated histones and methyl-specific histone binding proteins as the proof-of-principle, we determined that the new MTeC approach can compliment existing in vitro binding methods, and can also provide unique in vivo insights into PTM-dependent interactions. For example, we confirmed previous in vitro findings that endogenous HP1 preferentially binds H3K9me3. However, in contrast to recent in vitro observations, MTeC revealed that the tandem tudor domain-containing proteins, JMJD2A and 53BP1, display no preferential H4K20 methyl-selectivity in vivo. Last, by using MTeC in an unbiased manner to identify H3K9 methyl-specific PTMBPs, we determined that endogenous G9a binds methylated H3K9 in vivo. Further use of MTeC to characterize this interaction revealed that G9a selectively binds H3K9me1 in vivo, but not H3K9me2, contrary to recent in vitro findings. Although this study focused solely on methylated histones, we demonstrate how the innovative MTeC approach could be used to identify and characterize any PTMBP that binds any PTM on any protein in vivo.
Comparison of brain mechanisms underlying the processing of Chinese characters and pseudo‐characters: An event‐related potential study
Authors: Wang Ting , Li Hong , Zhang Qinglin , Tu Shen , Yu Caiyun , Qiu Jiang
Published: August 2009

Most Chinese characters are composed of a semantic radical on the left and a phonetic radical on the right. The semantic radical provides the semantic information; the phonetic radical provides information concerning the pronunciation of the whole character. The pseudo‐characters in the study consisted of different sub‐lexical parts of real Chinese characters and consequently they also had the semantic radical and the phonetic radical. But they were not readable and had no actual meaning. In order to investigate the spatiotemporal cortical activation patterns underlying the orthographic, phonological and semantic processing of Chinese characters, we used event‐related brain potentials (ERPs) to explore the processing of Chinese characters and pseudo‐characters when 14 healthy Chinese college students viewed the characters passively. Results showed that both Chinese characters and pseudo‐characters elicited an evident negative potential peaking around 120 ms (N120), which appeared to reflect initial orthographic distinction and evaluation. Then, Chinese pseudo‐characters elicited a more positive ERP deflection (P220) than did Chinese characters 200–250 ms after onset of the stimuli. It was similar to the recognition potential (RP) and might reflect the integration processes of phonological and semantic processing on the basis of early orthographic information. Dipole source analysis of the difference wave (pseudo‐characters minus characters) indicated that a generator localized in the left temporal‐occipital junction contributed to this effect, which was possibly related to phonological and perceptual–semantic information integration. Between 350–450 ms, a greater negativity (N360) in pseudo‐characters as compared to characters was found over midline fronto‐central scalp regions. Dipole analysis localized the generator of N360 in the right parahippocampal cortex. Therefore, the N360 might be an N400 component and reflect the higher‐level semantic activation on the basis of orthographic, phonological and perceptual–semantic processing.
The reactions of triethylamine-activated octasulfur with thioarsinites, L2As–SPh (L = Me, Ph), Bunsen’s cacodyl disulfide, Me2As(S)–S–AsMe2, and triphenylarsine
Authors: Sideris Theodore D. , Tsivgoulis Gerasimos M. , Vachliotis Dimitris G. , Ioannou Panayiotis V.
Published: August 2009

The reactions of L2As–SPh (L = Me or Ph) with varying amounts of octasulfur, activated by triethylamine, aiming at the preparation of L2As–S–AsL2 and L2As(S)–S–AsL2 were slow and very complex in the sense that the composition in solution changed on work up. Generally, the disulfide L2As(S)–S–AsL2 was formed admixed with L2As–S–NEt3+ and L2As–S−. The disulfide Ph2As(S)–S–AsPh2 was not stable during chromatography giving sulfur (S8) and Ph2As–S–AsPh2 which was autoxidized to Ph2AsO2H·Ph2As(S)OH. Bunsen’s cacodyl disulfide, Me2As(S)–S–AsMe2, was electrophilic toward activated octasulfur reacting at As = S sulfur. Triphenylarsine was oxidized to pure triphenylarsine sulfide in boiling ethanol by octasulfur in the presence of a catalytic amount of triethylamine in short time and with excellent yields.
Crystal supramolecularity of organic–inorganic hybrids of polyhalides: structures of 2,5-dibromopyrazinium triiodide and 2-bromopyridinium dibromoiodide
Authors: Ali Basem F. , Al-Far Rawhi , Haddad Salim F.
Published: August 2009

Crystal structure determinations of the compounds (C4H4Br2N2)+[I3]−, 1, and (C5H5BrN)+[IBr2]−, 2, have been carried out. In 1, the anion is surrounded symmetrically by four cations. This arrangement results from both (π)N–H ··· I–I–I and I–I–I ··· Br–C(π) intermolecular interactions, tying the cations and anion into sheets of pseudo four fold arrays of cations and anions. The crystal lattice of 2 consists of stacks of cations and anions that are connected via C–Br ··· Br–I–Br, N–H ··· Br–I–Br, and Br–I–Br ··· IBr2 inter-stacks intermolecular interactions leading to a supramolecular assembled lattice. The IBr2− anions are also assembled in a nearly T-shaped dimeric motif where one bromide end is interacting with the central iodide atom in another IBr2− unit (I–Br ··· I angle of 154°). The extensive anion ··· cation intermolecular interactions in both compounds lead to a crystal supramolecularity.
Long-term trends in major ions and nutrients in Lake Ontario
Authors: Dove Alice
Published: August 2009

The Great Lakes Surveillance Program has been monitoring water quality for almost 40 years in Lake Ontario. The program provides some of the most comprehensive, systematic and detailed information that is available in the world for such a large lake. The water quality in Lake Ontario has shown dramatic changes over the last 40 years, with the early measurements indicating high phosphorus concentrations that were subsequently reduced by management responses to the Great Lakes Water Quality Agreement. Other water quality parameters, such as some of the major ions, showed reductions during the 1970s and 1980s as well. Nitrate plus nitrite nitrogen has increased in the lake throughout the period of record, likely driven by increasing watershed and atmospheric sources. A major driver of more recent trends in water quality appears to be the invasion and subsequent expansion of invasive Dreissena mussel populations that first appeared in Lake Ontario in 1989. Total phosphorus concentrations have further declined, and the proportion of total phosphorus that is soluble is increasing, possibly due to the filtering action of these mussels. Concentrations of major ions that are incorporated in mussel shells such as calcium have declined, while those that do not, such as magnesium, have increased. Spring silica concentrations are increasing; an ominous signal of declining diatom populations, which may also be a symptom of the proliferation of invasive mussels in the lake.
Addition of round gobies to the prey community of Lake Ontario and potential implications to thiamine status and reproductive success of Lake Trout
Authors: Fitzsimons J. D. , Clark M. , Keir M.
Published: August 2009

The addition of round goby to the Lake Ontario prey fish community can, because it appears to lack thiaminase, ameliorate the effects of a diet high in thiaminase-rich alewives associated with a thiamine deficiency in Lake Trout. However, the effects of round goby predation may negate such effects. We conducted studies to assess the proportion, by weight, of round gobies in the diet of contemporary Lake Ontario Lake Trout and predicted its effect on egg thiamine concentration, and early mortality syndrome (EMS) and growth retardation, two indicators of thiamine deficiency. We compared these parameters to that for the historic prey community, as well as possible future diet scenarios with progressively greater proportions of round goby (e.g. 50, 75 and 100%). To assess the combined and separate effects of the thiamine deficiency we used a modeling approach to determine the effect of EMS (70%) typical of Lake Ontario Lake Trout, growth retardation, density of Lake Trout egg (e.g. 100, 500, 1000, and 5000 eggs m−2) and round goby (e.g. 1, 9, 18, 35, 75, 150 gobies m−2), three separate durations of round goby residence on Lake Trout spawning habitat (e.g. 30, 60 and 213 days), and at either a shallow water or deepwater temperature regime. Eight years after first invading Lake Ontario, the proportion of round gobies in Lake Trout diets remains low, although the highest observed (25%) would result in significant amelioration of the thiamine deficiency from past conditions. Modeling indicated that the negative effects associated with round goby predation on eggs and fry could easily exceed any positive effects resulting from amelioration of the thiamine deficiency by a diet containing round goby. The effects of goby predation were found to be dependent on density of both Lake Trout eggs and round gobies, and while predation effects were minimally affected by temperature regime, they were highly dependent on the period of round goby residence on Lake Trout spawning habitat.
A comparison of frameworks and objectives for implementation of marine protected areas in Northern Europe and in Southeast Asia
Authors: Sørensen Thomas Kirk , Thomsen Linda Nguyen
Published: August 2009

A proliferation of marine protected areas around the world, including Europe and Southeast Asia, is evidence of a growing global concern for the marine environment and its living resources. While marine protected areas in Europe on a wider scale have generally been considered a tool for either nature conservation or a technical measure in management of fisheries, overall management objectives of marine protected areas in Southeast Asian countries have varied more significantly between countries and sites due to differences in societal needs and opportunities, spatial scales, environmental conditions and varying threats. These differences have resulted in different approaches to marine protected area development and management.

Management of the Northern European marine environment and its living resources is highly sectoral and largely determined by central directives and policies stemming from the European Union, such as the Habitats Directive and the Common Fisheries Policy. This paper however, will touch upon an ongoing evolution within the European Union from a strictly sectoral approach to marine protected areas and marine management, towards a more integrated, ecosystem approach to management of fisheries and the marine environment.

In Southeast Asia, marine protected area development is usually determined by individual governments, municipalities and coastal communities, based upon specific needs and settings. Examples of such marine protected areas in Vietnam and the Philippines will be described, including their underlying institutional frameworks and objectives such as tourism, management of artisanal fisheries, etc.

Examples of differences and similarities between Northern European and Southeast Asian marine protected areas will be presented and areas in which regions might learn from one another identified. For instance, where Southeast Asian protected areas have addressed the inevitable interdependency between healthy ecosystems and sustainable coastal fisheries for decades, marine protected areas in Northern Europe usually address either large scale management of stocks of individual fish species or nature conservation. Tourism has long been an overarching driving force in marine protected area implementation in SE Asia, while in Northern Europe especially this has only had little influence on overall objectives pertaining to the marine environment.
Assessment of some marine ecosystems using sustainable utilization indicators in Hai Phong—Quang Ninh coastal area, Vietnam
Authors: Lan Tran Dinh
Published: August 2009

This study is aimed at analyzing key indicators for the evaluation of changes and tendencies of sustainable utilization and management in some marine ecosystems in the coastal waters of Hai Phong - Quang Ninh area. To complete this study, the methods employed consisted of the application of remote sensing data and geographic information systems to extract information on spatial distribution of mangrove and tidal flat ecosystems, as well as on the reclamation area for human development and indicator investigation and analysis, using remote sensing extracted and field survey monitored data with Microsoft Excel (MS Excel). Applying indicators for sustainable utilization and management of marine ecosystems, developed in recent studies for the Hai Phong - Quang Ninh area, demonstrated changes and trends in significant ecosystems, such as coral reefs and mangroves. The outcomes showed that from 1998 to 2003, living coral cover was reduced by 20% on average in the Ha Long Bay area and by 13% in Cat Ba (Hang Trai - Dau Be), and projected that living coral cover would be reduced by a further 10% to 50% by 2010. The number of coral species was much reduced by 15% to 72% in the Ha Long—Cat Ba area. Mangrove area also decreased between 1995 and 2004, particularly after 2000, and is projected to be only 10,000 ha in 2010 in Quang Ninh. Marine ecosystems in the coastal waters of Hai Phong - Quang Ninh area have degraded significantly, particularly coral reefs, mangroves and tidal flats.
Dams and fisheries in the Mekong Basin
Authors: Baran E. , Myschowoda C.
Published: August 2009

This paper draws on approaches in ecology, biology and policy analysis to examine the tensions between dams and fisheries in the Lower Mekong Basin. We review the exceptional importance of Mekong fisheries in terms of total catch, economic value and their role in rural livelihoods. The ecological conditions necessary to sustain the fish production are also analysed. The paper then considers the implications of dam development in the Mekong Basin, drawing on recent research to review predicted changes in hydrology and the resulting impacts on fishery resources. We then consider why, given the importance of fisheries, these potential impacts are not being addressed in regional policy processes.
Abundance and composition of zooplankton in the Straits of Malacca
Authors: Rezai H. , Yusoff F. M. , Arshad A. , Othman B. H. R.
Published: August 2009

The zooplankton composition and distribution were studied during four oceanographic cruises in the Straits of Malacca between November 1998 and August 2000 with 140 μm-mesh and 45-cm diameter NORPAC net. Zooplankton samples were analyzed for the faunal composition and abundance. Zooplankton abundance peaked during pre-southwest monsoon (mean of 12, 918 ± 5, 635 ind. m3). Copepods were the most important constituents of the zooplankton in all areas. Copepods (including copepodites) accounted for 71.3%, 71.2%, 70.9% and 57.9% of the total zooplankton populations during consecutive cruises I, II, III and IV, respectively. Molluscs (6.3% to 12.4%) and crustacean's nauplii (4.4% to 6.0%) comprised the important groups of non-copepod zooplankton. Spatio-temporal variation in zooplankton abundance was not statistically significant. Zooplankton was more abundant in the near-coastal areas than in offshore areas, but the difference was not significant.