bluuebunny/crossref_metadata_2025 huggingface dataset:
NO2columns in the western United States observed from space and simulated by a regional chemistry model and their implications for NOxemissions
Authors: Kim S.‐W. , Heckel A. , Frost G. J. , Richter A. , Gleason J. , Burrows J. P. , McKeen S. , Hsie E.‐Y. , Granier C. , Trainer M.
Published: June 2009

There are many isolated sources of NOxemissions across the western United States, including electrical power generation plants and urban areas. In this manuscript, two satellite instruments measuring NO2vertical columns over these sources and an atmospheric chemical‐transport model are used to evaluate bottom‐up NOxemission inventories, model assumptions, and satellite retrieval algorithms. We carried out simulations with the Weather Research and Forecasting‐Chemistry (WRF‐Chem) model for the western U.S. domain during the summer of 2005 using measured power plant NOxemissions. Model NO2vertical columns are compared with a retrieval of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) satellite instrument data by the University of Bremen and retrievals of the Ozone Monitoring Instrument (OMI) data by the U.S. National Aeronautics and Space Administration (NASA) and a modified version of the NASA OMI retrieval produced by the University of Bremen. For areas dominated by power plant NOxemissions, the model NO2columns serve as a comparison standard for satellite retrievals because emissions are continuously monitored at all large U.S. power plants. An extensive series of sensitivity tests of the assumptions in both the satellite retrievals and the model are carried out over the Four Corners and San Juan power plants, two adjacent facilities in the northwest corner of New Mexico that together represent the largest NOxpoint source in the United States. Overall, the SCIAMACHY and OMI NO2columns over western U.S. power plants agree well with model NO2columns, with differences between the two being within the variability of the model and satellite. In contrast to regions dominated by power plant emissions, model NO2columns over large urban areas along the U.S. west coast are approximately twice as large as satellite NO2columns from SCIAMACHY and OMI retrievals. The discrepancies in urban areas are beyond the sensitivity ranges in the model simulations and satellite observations, implying overestimates of these cities' bottom‐up NOxemissions, which are dominated by motor vehicles. Taking the uncertainties in the satellite retrievals into account, our study demonstrates that the tropospheric columns of NO2retrieved from space‐based observations of backscattered solar electromagnetic radiation can be used to evaluate and improve bottom‐up emission inventories.
Electrodynamical control of the ambient ionization near the equatorial anomaly crest in the Indian zone during counter electrojet days
Authors: Hajra R. , Chakraborty S. K. , Paul A.
Published: June 2009

The variability of ambient ionization near the crest of the equatorial anomaly on the days of counter electrojet (CEJ) is studied using a long‐term (1980–1990) database of total electron content (TEC) obtained from Calcutta (geographic: longitude, 88.38°E; latitude, 22.58°N; dip: 32°N), situated virtually below the northern crest of the equatorial anomaly, in conjunction with the equatorial electrojet (EEJ) data of the Indian subcontinent and foF2 data from the equatorial stations. On the days of CEJ events the diurnal variations of TEC exhibit deviations (decreases) from monthly mean values, but the feature is not regular throughout the observing period. A larger percentage of CEJ days show decreases in the descending phase (1980–1985) of solar cycle compared to the ascending one (1986–1990). During low to moderate solar activity years the ionosphere near the anomaly crest is found to be more susceptible to CEJ related equatorial electrodynamics than in the high solar activity periods. On the seasonal basis, though the solstitial months of ascending phase exhibit higher percentage occurrence of decreases, the feature is not so prominent in the descending epoch. An attempt is made to relate the decreases in TEC with the prevailing electrodynamics at the magnetic equator for which EEJ, under quiet geomagnetic conditions, may be treated as a proxy index. A statistical analysis reveals positive correlations of TEC decreases with strength and duration of CEJ but anticorrelations with rising slope, strength, and time‐integrated value of EEJ as well as initiation time of CEJ. To represent better correspondence of the TEC variability with the equatorial electrodynamics a function combining various EEJ parameters has been generated, which seems to exhibit significant association with TEC decreases on the days of CEJ events.
Self‐scattering of a powerful HF radio wave on stimulated ionospheric turbulence
Authors: Zalizovski A. V. , Kashcheyev S. B. , Yampolski Y. M. , Galushko V. G. , Belyey V. , Isham B. , Rietveld M. T. , La Hoz C. , Brekke A. , Blagoveshchenskaya N. F. , Kornienko V. A.
Published: June 2009

An analysis is presented of high‐frequency (HF) signals from the European Incoherent Scatter HF ionospheric modification transmitter received during 26–30 October 2002 at three sites, two in Europe and one in Antarctica. Two components with different characteristics (“mirror‐reflected” and “scattered”) were observed in the signal spectra. The mirror‐reflected component can be associated with radiation through the side lobes of the transmitting antenna thus bypassing the modified volume on its way to the receiving sites. In contrast, the scattered component was radiated through the main antenna beam and then scattered by pump‐induced ionospheric irregularities above the heater. As a result, variations in the scattered component signal intensity and Doppler frequency shifts (DFS) recorded at the greatly separated sites showed a high level of correlation. It is shown that the Doppler frequency variations can be associated with variations in the plasma density and/or physical motion velocities of stimulated inhomogeneities within the volume common to all propagation paths. Analysis of Doppler frequency shifts at greatly separated sites would allow identifying the mechanism responsible for the self‐scattering effect. In the case of DFSs due to motion of the pump‐induced scatterers it would be also possible to reconstruct the full velocity vector of the inhomogeneities.
NASA Mission to Explore Forcing of Earth's Space Environment
Authors: Eastes Richard
Published: June 2009

The Global‐Scale Observations of the Limb and Disk (GOLD) mission has been selected as a mission of opportunity by NASA's Small Explorer program. This mission, with an anticipated 2014 launch date, is an opportunity to significantly advance thermosphere‐ionosphere (TI) science and to provide answers to key elements of an overarching question for heliophysics science: What is the global‐scale response of the thermosphere and ionosphere to forcing (e.g., by geomagnetic storms or atmospheric tides) in the integrated Sun‐Earth system?
Obama Indicates Strong Support for Science
Authors: Showstack Randy
Published: June 2009

In remarks delivered at the U.S. National Academy of Sciences (NAS) annual meeting on 27 April, U.S. President Barack Obama indicated his administration's strong support for science and for pursuing a clean energy economy. He also announced a goal that the United States “will devote more than 3% of our [gross domestic product] to research and development.”

“This represents the largest commitment to scientific research and innovation in American history,” Obama said, noting that the American Recovery and Reinvestment Act already is providing the nation with its largest single boost to investment in basic research.
Outstanding Student Paper Awards
Authors: Anonymous
Published: June 2009

The following members received Outstanding Student Paper Awards at the 2008 AGU Fall Meeting in San Francisco, Calif. Awards for other sections and focus groups will be announced in subsequent issues of Eos.
Crustal noble gases in deep brines as natural tracers of vertical transport processes in the Michigan Basin
Authors: Ma Lin , Castro Maria Clara , Hall Chris M.
Published: June 2009

Noble gas concentrations and isotopic ratios are presented for 38 deep (∼0.5–3.6 km) brine samples in the Michigan Basin. These brine samples clearly show the presence of an important crustal component of 4He, 21Ne, 40Ar, and 136Xe. Both 40Arcrust and 136Xecrust display the presence of a strong vertical gradient along the sedimentary strata of the basin. We show that the in situ production for these two gases within the sedimentary strata is insufficient to account for the observed crustal component in the Michigan brines. These point to the presence of a deep, external source for crustal noble gases, likely the Precambrian crystalline basement beneath the Michigan Basin. Furthermore, observed elemental ratios of crustal noble gases (4He/40Ar, 21Ne/40Ar, 4He/136Xe, and 21Ne/136Xe) in these brines vary over several orders of magnitude with respect to the expected production ratios from the crystalline basement rocks and display a systematic pattern within the basin. Specifically, samples above the Salina Group (shallow formations) are relatively enriched in 4Hecrust and 21Necrust with respect to 40Arcrust and 136Xecrust, as opposed to those below the massive Salina evaporite layer (deeper formations) which exhibit complementary patterns. We show that such a general trend is best explained by a Rayleigh‐type elemental fractionation model involving upward transport of crustal noble gases and associated elemental fractionation processes, controlled by both diffusion‐ and solubility‐related mechanisms. As previously indicated by the mantle and atmospheric noble gas signatures in these same Michigan brine samples, release of deep crustal noble gases into the basin is yet another independent indicator pointing to the occurrence of a past thermal event in the basin. We suggest that recent reactivation of the ancient midcontinent rift system underneath the Michigan Basin is likely responsible for the upward transport of heat and loss of the atmospheric noble gas component, as well as release of crustal (still ongoing) and mantle noble gases into the basin via deep‐seated faults and fracture zones. Such a model also supports an internal heat source hypothesis as being largely responsible for the existence of past high temperatures in the basin without involvement of large‐scale brine migration from peripheral forming orogenic fold belts.
Cul3-mediated Nrf2 ubiquitination and antioxidant response element (ARE) activation are dependent on the partial molar volume at position 151 of Keap1
Authors: Eggler Aimee L. , Small Evan , Hannink Mark , Mesecar Andrew D.
Published: June 2009

Nrf2 (nuclear factor erythroid 2-related factor 2) is a transcription factor that activates transcription of a battery of cytoprotective genes by binding to the ARE (antioxidant response element). Nrf2 is repressed by the cysteine-rich Keap1 (kelch-like ECH-associated protein 1) protein, which targets Nrf2 for ubiquitination and subsequent degradation by a Cul3 (cullin 3)-mediated ubiquitination complex. We find that modification of Cys151 of human Keap1, by mutation to a tryptophan, relieves the repression by Keap1 and allows activation of the ARE by Nrf2. The Keap1 C151W substitution has a decreased affinity for Cul3, and can no longer serve to target Nrf2 for ubiquitination, though it retains its affinity for Nrf2. A series of 12 mutant Keap1 proteins, each containing a different residue at position 151, was constructed to explore the chemistry required for this effect. The series reveals that the extent to which Keap1 loses the ability to target Nrf2 for degradation, and hence the ability to repress ARE activation, correlates well with the partial molar volume of the residue. Other physico-chemical properties do not appear to contribute significantly to the effect. Based on this finding, a structural model is proposed whereby large residues at position 151 cause steric clashes that lead to alteration of the Keap1–Cul3 interaction. This model has significant implications for how electrophiles which modify Cys151, disrupt the repressive function of Keap1.
Perspectives on AAC Intervention in School Settings
Authors: Warren Lori , Warren Faye
Published: June 2009

This article presents the perspective of a parent and an AAC device user on the importance of focused intervention on language development with individuals with complex communication needs who use AAC devices. The parent perspective outlines the speech-language pathology treatment story of her child. Using that lessons of that story, the parent challenges readers to advocate for the development of long-range language development planning and implementation of an AAC language development curriculum. In addition, the parent emphasizes the need for strong collaborative team building in order to support effective language intervention programs. The user perspective highlights the issue of core vocabulary, advanced vocabulary building, and traditional intervention on syntax, morphology, and discourse development. The reader is strongly urged to maintain focus on language development, rather than technology or device operation, as the essential element of life-long success for individuals using AAC devices.
AAC and the IEP
Authors: Hurd Robin
Published: June 2009

The team in IEP team is a necessity for students with complex communication needs. These students need the expertise of each team member to design a custom education that allows them to make progress towards state educational standards and build communication competence across curriculum areas. This article covers the strengths each team member brings to the IEP team. Parents bring a long-term perspective of the student; general education teachers bring their knowledge of what curriculum will be covered in the inclusion classroom; and special education teachers bring their training in working with and making adaptations for students with special needs. The article also focuses specifically on ways the speech-language pathologist contributes information on how language is used across the curriculum. A vital part of the role of the SLP on the IEP team is to pinpoint specific areas of language need and to provide teachers with ways to address those areas of need within their curriculum.
Mode-locking nanoporous alumina membrane embedded with carbon nanotube saturable absorber
Authors: Kurashima Yuichi , Yokota Yoshihiko , Miyamoto Iwao , Kataura Hiromichi , Sakakibara Youichi
Published: June 2009

The saturable absorption effect of semiconducting single-wall carbon nanotubes (SWCNTs) covering the near-infrared region is promising for mode-locking devices of short pulse lasers. However, an issue remains that the heat generated at the SWCNTs would destroy the devices. In this research, we fabricated a nanostructured heat sink in which the SWCNTs are stuffed into specially developed nanopores of heat conductive alumina. Actually, it induced stable mode-locked operation of an Er fiber laser for over 4 months.
Model-based analysis of sugar accumulation in response to source - sink ratio and water supply in grape (Vitis vinifera) berries
Authors: Dai Zhan Wu , Vivin Philippe , Robert Thierry , Milin Sylvie , Li Shao Hua , Génard Michel
Published: June 2009

The dynamics of sugar (hexose) concentration in ripening grape berries (Vitis vinifera L.) were simulated with a refined mechanistic model. Changes in sugar concentration were reproduced by the sum of sugar import (S), sugar metabolism (M) and water budget (W). S and W were derived from model inputs of fresh and dry mass, and M was simulated with a relative metabolism rate describing the depletion of hexose. The relative metabolism rate was associated with the relative growth rate of dry mass with a coefficient (k) that was constant for a given cultivar under various growth conditions (temperature, water supply, and source–sink ratio) but varied with genotype. The k value was ~20% higher for cv. Merlot than for cv. Cabernet Sauvignon, indicating more imported sugars would be depleted by Merlot than Cabernet Sauvignon. The model correctly simulated the negative effect of lowered leaf-to-fruit  ratio and the positive effect of water shortage on sugar concentration. Sensitivity analysis revealed that the present model was weakly sensitive to k because of sugar accumulation being predominantly controlled by S, with M relatively small (~20%) with respect to the increment of sugar concentration. Model simulation indicated that the decreasing leaf-to-fruit ratio reduced S more than M and W, causing a net decrease in sugar concentration. In contrast, the water shortage decreased S less than M and W, resulting in a net increase in sugar concentration.
Heat acclimation induced acquired heat tolerance and cross adaptation in different grape cultivars: relationships to photosynthetic energy partitioning
Authors: Wang Li-Jun , Loescher Wayne , Duan Wei , Li Wei-Dong , Yang Shu-Hua , Li Shao-Hua
Published: June 2009

Several mechanisms on acquired heat tolerance and cross adaptation have been proposed; however, relationships to photosynthetic energy partitioning remain unknown. The effects of heat pretreatment on cold and heat tolerance in grapevine leaves of two cultivars (‘Jingxiu’, cold sensitive; ‘Beta’, cold tolerant) were evident in changes in the antioxidant system, lipid peroxidation, net photosynthesis rate and also in chlorophyll fluorescence according : Y(II) + Y(NPQ) + Y(NO) = 1, where Y(II) is the effective PSII quantum yield; Y(NPQ) is regulated energy dissipation as a protective mechanism; and Y(NO) is non-regulated energy dissipation as a damaging mechanism. Heat pretreatment enhanced heat tolerance in the two cultivars, which was associated with less energy partitioned in non-regulated energy dissipation, less lipid peroxidation and higher antioxidant enzyme (catalase, ascorbate peroxidase and guaiacol peroxidase) activities compared with control plants under heat stress. Heat pretreatment also induced cold tolerance in ‘Jingxiu’ and ‘Beta’ leaves. This cross adaptation seemed to be attributable in part to less non-regulated energy dissipation in pretreated ‘Jingxiu’ and ‘Beta’ than the controls under cold stress. The evidence that lipid peroxidation was less and antioxidant enzyme activities were higher in pretreated plants under cold stress further corroborated the results from energy partitioning.
Fumigation of rabbit warrens with chloropicrin produces poor welfare outcomes - a review
Authors: Marks Clive A.
Published: June 2009

Chloropicrin (CLPN) is used in Australia and New Zealand as a warren fumigant for the control of exotic European rabbits (Oryctolagus cuniculus) but is no longer registered for this purpose in the United States or the European Union. This review summarises the mammalian toxicology and clinical records from 56 accounts where signs, symptoms and pathology have been related to a range of CLPN concentrations. The approach follows a general principle where an assessment of the humaneness of vertebrate pest control techniques should be firstly based upon a thorough synopsis of published behavioural, physiological and pathological impacts. Chloropicrin produces intense irritation by stimulation of trigeminal nerves and brief exposures to concentrations of ≤1 ppm can severely irritate the eyes and cause lacrimation in mammals. Beyond 8 ppm, exposures are reported to be painful and incapacitating in humans. Mammals experience an array of common signs and symptoms including: headache, nausea, diarrhoea, laboured breathing, decrease in spontaneous motor activity, salivation, rhinorrhea, blood stains around the nose and mouth, painful irritation of mucous membranes, profuse lacrimation, audible obstruction of respiration and distress vocalisation. Acute pathological changes from CLPN exposure can cause death in mammals from pulmonary oedema, bronchopneumonia, emphysema or general destructive changes and necrosis of the small and medium bronchi. Overall, the signs, symptoms and pathology arising from CLPN exposure at any airborne concentration beyond 0.3 ppm indicate that it must be assumed to cause suffering in all mammals. Exposure to CLPN that is not acutely lethal may debilitate rabbits and other species and cause a protracted death over hours or days. To produce a humane death a fumigant must be non-irritating, have an initial depressive action on the central nervous system and/or produce a rapid death without protracted distress while having little ability to cause debilitation or chronic injury. Given that CLPN has none of these characteristics, it cannot be considered to be acceptably humane.
Can a predator see 'invisible' light? Infrared vision in ferrets (Mustelo furo)
Authors: Newbold Haylie G. , King Carolyn M.
Published: June 2009

Infrared (wavelengths >750 nm) light-emitting equipment is commonly used worldwide to monitor nocturnal predator and prey behaviour. However, it is possible that the infrared (IR)-light wavelengths emitted from the equipment are so close to the spectral threshold of some key species that the light may be detected. An operant procedure was used to test whether five male ferrets (Mustela furo) could see an IR light with peak wavelengths of 870 and 920 nm. First, the ferrets were taught to press a lever under a lit white light for food reinforcement (overall mean response accuracy was 89%). Changing the properties (wavelength and intensity) of the light did not disrupt the ferrets’ abilities to perform the learned task. When the light was changed to IR (870 nm), four of five ferrets responded to the light at levels significantly higher than chance (mean = 68%, n = 4188, P < 0.01). When glare from a red trial-starting light was removed, two of the five ferrets (S3 and S4) showed strong evidence (response accuracies of 84% and 78%, respectively, P < 0.01) that they could see IR at 870 nm; however, S3 definitely could not see IR at 920 nm (n = 124, mean = 47%, P = 0.53). We conclude that at least some ferrets can see the light emitted from standard monitoring equipment that uses IR wavelengths of ~870 nm. To ensure nocturnal predator and prey behaviours are not altered by IR surveillance, field programs should use only high-wavelength IR diodes (at least 920 nm).
Manage one beach or two? Movements and space-use of the threatened hooded plover (Thinornis rubricollis) in south-eastern Australia
Authors: Weston Michael A. , Ehmke Glenn C. , Maguire Grainne S.
Published: June 2009

An understanding of space use and dispersal of a wildlife species is essential for effective management. We examined the movements of a beach-dwelling, threatened population of hooded plover (Thinornis rubricollis) in southern central Victoria, Australia, by analysing sightings of colour-banded birds (4897 sightings; 194 birds tracked for up to 9 years). Most movements were relatively short (5050 ± 305 m), with 61.4% <1 km and 95.3% <20 km; they lacked directional or sexual bias. The extent of coastline used by individual birds was 47.8 ± 58.0 km. Regional differences in average distances moved by adults were apparent. For adults, movement rates (mean distance per day) were higher during the non-breeding season than during the breeding season. Non-breeding adults generally remained close to their partners (non-breeding, 456.3 ± 163.9 m; breeding, 148.2 ± 45.3 m). Largest flock sizes were recorded during the non-breeding period, and flocking was not uniformly distributed along the coast but appeared to be concentrated in particular locations. The frequency of pair cohesion (i.e. when the distance between partners was zero on a given day) was similar during the breeding (69.6%) and non-breeding seasons (67.7%). Breeding territories (kernel analysis) were 36.7 ± 5.7 ha and overlapped from year to year in all cases (23 pairwise comparisons; 47.9 ± 7.1% overlap). The high fidelity and constancy of territories confirms they warrant ongoing management investment, although the species relies on a matrix of breeding and non-breeding sites. The latter appear to occur in specific parts of the coast and warrant enhanced protection and more research attention. Fragmentation of the breeding population might occur where habitat is rendered unsuitable for > ~50 km.
Kinetic control of negative feedback regulators of NF-κB/RelA determines their pathogen- and cytokine-receptor signaling specificity
Authors: Shih Vincent F.-S. , Kearns Jeffrey D. , Basak Soumen , Savinova Olga V. , Ghosh Gourisankar , Hoffmann Alexander
Published: June 2009

Mammalian signaling networks contain an abundance of negative feedback regulators that may have overlapping (“fail-safe”) or specific functions. Within the NF-κB signaling module, IκBα is known as a negative feedback regulator, but the newly characterized inhibitor IκBδ is also inducibly expressed in response to inflammatory stimuli. To examine IκBδ's roles in inflammatory signaling, we mathematically modeled the 4-IκB-containing NF-κB signaling module and developed a computational phenotyping methodology of general applicability. We found that IκBδ, like IκBα, can provide negative feedback, but each functions stimulus-specifically. Whereas IκBδ attenuates persistent, pathogen-triggered signals mediated by TLRs, the more prominent IκBα does not. Instead, IκBα, which functions more rapidly, is primarily involved in determining the temporal profile of NF-κB signaling in response to cytokines that serve intercellular communication. Indeed, when removing the inducing cytokine stimulus by compound deficiency of the
tnf
gene, we found that the lethality of
i
κ
b
α
−/−
mouse was rescued. Finally, we found that IκBδ provides signaling memory owing to its long half-life; it integrates the inflammatory history of the cell to dampen NF-κB responsiveness during sequential stimulation events.
Genomic linkage of male song and female acoustic preference QTL underlying a rapid species radiation
Authors: Shaw Kerry L. , Lesnick Sky C.
Published: June 2009

The genetic coupling hypothesis of signal-preference evolution, whereby the same genes control male signal and female preference for that signal, was first inspired by the evolution of cricket acoustic communication nearly 50 years ago. To examine this hypothesis, we compared the genomic location of quantitative trait loci (QTL) underlying male song and female acoustic preference variation in the Hawaiian cricket genusLaupala. We document a QTL underlying female acoustic preference variation between 2 closely related species (Laupala kohalensisandLaupala paranigra). This preference QTL colocalizes with a song QTL identified previously, providing compelling evidence for a genomic linkage of the genes underlying these traits. We show that both song and preference QTL make small to moderate contributions to the behavioral difference between species, suggesting that divergence in mating behavior amongLaupalaspecies is due to the fixation of many genes of minor effect. The diversity of acoustic signaling systems in crickets exemplifies the evolution of elaborate male displays by sexual selection through female choice. Our data reveal genetic conditions that would enable functional coordination between song and acoustic preference divergence during speciation, resulting in a behaviorally coupled mode of signal-preference evolution. Interestingly,Laupalaexhibits one of the fastest rates of speciation in animals, concomitant with equally rapid evolution in sexual signaling behaviors. Genomic linkage may facilitate rapid speciation by contributing to genetic correlations between sexual signaling behaviors that eventually cause sexual isolation between diverging populations.
Proximity of excitatory and inhibitory axon terminals adjacent to pyramidal cell bodies provides a putative basis for nonsynaptic interactions
Authors: Merchán-Pérez Angel , Rodriguez José-Rodrigo , Ribak Charles E. , DeFelipe Javier
Published: June 2009

Although pyramidal cells are the main excitatory neurons in the cerebral cortex, it has recently been reported that they can evoke inhibitory postsynaptic currents in neighboring pyramidal neurons. These inhibitory effects were proposed to be mediated by putative axo-axonic excitatory synapses between the axon terminals of pyramidal cells and perisomatic inhibitory axon terminals [Ren M, Yoshimura Y, Takada N, Horibe S, Komatsu Y (2007)
Science
316:758–761]. However, the existence of this type of axo-axonic synapse was not found using serial section electron microscopy. Instead, we observed that inhibitory axon terminals synapsing on pyramidal cell bodies were frequently apposed by terminals that established excitatory synapses with neighbouring dendrites. We propose that a spillover of glutamate from these excitatory synapses can activate the adjacent inhibitory axo-somatic terminals.
Gender, culture, and mathematics performance
Authors: Hyde Janet S. , Mertz Janet E.
Published: June 2009

Using contemporary data from the U.S. and other nations, we address 3 questions: Do gender differences in mathematics performance exist in the general population? Do gender differences exist among the mathematically talented? Do females exist who possess profound mathematical talent? In regard to the first question, contemporary data indicate that girls in the U.S. have reached parity with boys in mathematics performance, a pattern that is found in some other nations as well. Focusing on the second question, studies find more males than females scoring above the 95th or 99th percentile, but this gender gap has significantly narrowed over time in the U.S. and is not found among some ethnic groups and in some nations. Furthermore, data from several studies indicate that greater male variability with respect to mathematics is not ubiquitous. Rather, its presence correlates with several measures of gender inequality. Thus, it is largely an artifact of changeable sociocultural factors, not immutable, innate biological differences between the sexes. Responding to the third question, we document the existence of females who possess profound mathematical talent. Finally, we review mounting evidence that both the magnitude of mean math gender differences and the frequency of identification of gifted and profoundly gifted females significantly correlate with sociocultural factors, including measures of gender equality across nations.
Sorting in early endosomes reveals connections to docking- and fusion-associated factors
Authors: Barysch Sina V. , Aggarwal Shweta , Jahn Reinhard , Rizzoli Silvio O.
Published: June 2009

The early endosomes constitute a major sorting platform in eukaryotic cells. They receive material through fusion with endocytotic vesicles or with trafficking vesicles from the Golgi complex and later sort it into budding vesicles. While endosomal fusion is well understood, sorting is less characterized; the 2 processes are generally thought to be effected by different, unrelated machineries. We developed here a cell-free assay for sorting/budding from early endosomes, by taking advantage of their ability to segregate different cargoes (such as transferrin, cholera toxin subunit B, and low-density lipoprotein, LDL) into different carrier vesicles. Cargo separation required both carrier vesicle formation and active maturation of the endosomes. Sorting and budding were insensitive to reagents perturbing clathrin coats, coatomer protein complex-I (COPI) coats, dynamin, and actin, but were inhibited by anti-retromer subunit antibodies. In addition, the process required Rab-GTPases, phosphatidylinositol-3-phosphate, and, surprisingly, the docking factor early endosomal autoantigen 1 (EEA1). Sorting also required the function of the
N
-ethylmaleimide-sensitive factor (NSF), a well-known fusion cofactor, while it did not depend on preceding fusion of endosomes. We conclude that fusion, docking, and sorting/budding are interconnected at the molecular level.
Scaffold expulsion and genome packaging trigger stabilization of herpes simplex virus capsids
Authors: Roos Wouter H. , Radtke Kerstin , Kniesmeijer Edward , Geertsema Hylkje , Sodeik Beate , Wuite Gijs J. L.
Published: June 2009

Herpes simplex virus type 1 (HSV1) capsids undergo extensive structural changes during maturation and DNA packaging. As a result, they become more stable and competent for nuclear egress. To further elucidate this stabilization process, we used biochemical and nanoindentation approaches to analyze the structural and mechanical properties of scaffold-containing (B), empty (A), and DNA-containing (C) nuclear capsids. Atomic force microscopy experiments revealed that A and C capsids were mechanically indistinguishable, indicating that the presence of DNA does not account for changes in mechanical properties during capsid maturation. Despite having the same rigidity, the scaffold-containing B capsids broke at significantly lower forces than A and C capsids. An extraction of pentons with guanidine hydrochloride (GuHCl) increased the flexibility of all capsids. Surprisingly, the breaking forces of the modified A and C capsids dropped to similar values as those of the GuHCl-treated B capsids, indicating that mechanical reinforcement occurs at the vertices. Nonetheless, it also showed that HSV1 capsids possess a remarkable structural integrity that was preserved after removal of pentons. We suggest that HSV1 capsids are stabilized after removal of the scaffold proteins, and that this stabilization is triggered by the packaging of DNA, but independent of the actual presence of DNA.
Sustained
Neurog3
expression in hormone-expressing islet cells is required for endocrine maturation and function
Authors: Wang Sui , Jensen Jan N. , Seymour Philip A. , Hsu Wei , Dor Yuval , Sander Maike , Magnuson Mark A. , Serup Palle , Gu Guoqiang
Published: June 2009

Neurog3 (Neurogenin 3 or Ngn3) is both necessary and sufficient to induce endocrine islet cell differentiation from embryonic pancreatic progenitors. Since robust
Neurog3
expression has not been detected in hormone-expressing cells, Neurog3 is used as an endocrine progenitor marker and regarded as dispensable for the function of differentiated islet cells. Here we used 3 independent lines of
Neurog3
knock-in reporter mice and mRNA/protein-based assays to examine
Neurog3
expression in hormone-expressing islet cells.
Neurog3
mRNA and protein are detected in hormone-producing cells at both embryonic and adult stages. Significantly, inactivating
Neurog3
in
insulin
-expressing β cells at embryonic stages or in
Pdx1
-expressing islet cells in adults impairs endocrine function, a phenotype that is accompanied by reduced expression of several
Neurog3
target genes that are essential for islet cell differentiation, maturation, and function. These findings demonstrate that
Neurog3
is required not only for initiating endocrine cell differentiation, but also for promoting islet cell maturation and maintaining islet function.
Classical cadherins control nucleus and centrosome position and cell polarity
Authors: Dupin Isabelle , Camand Emeline , Etienne-Manneville Sandrine
Published: June 2009

Control of cell polarity is crucial during tissue morphogenesis and renewal, and depends on spatial cues provided by the extracellular environment. Using micropatterned substrates to impose reproducible cell–cell interactions, we show that in the absence of other polarizing cues, cell–cell contacts are the main regulator of nucleus and centrosome positioning, and intracellular polarized organization. In a variety of cell types, including astrocytes, epithelial cells, and endothelial cells, calcium-dependent cadherin-mediated cell–cell interactions induce nucleus and centrosome off-centering toward cell–cell contacts, and promote orientation of the nucleus–centrosome axis toward free cell edges. Nucleus and centrosome off-centering is controlled by N-cadherin through the regulation of cell interactions with the extracellular matrix, whereas the orientation of the nucleus–centrosome axis is determined by the geometry of N-cadherin–mediated contacts. Our results demonstrate that in addition to the specific function of E-cadherin in regulating baso-apical epithelial polarity, classical cadherins control cell polarization in otherwise nonpolarized cells.
Monitoring the Effectiveness of Hospital Cleaning Practices by Use of an Adenosine Triphosphate Bioluminescence Assay
Authors: Boyce John M. , Havill Nancy L. , Dumigan Diane G. , Golebiewski Michael , Balogun Ola , Rizvani Ramo
Published: June 2009

Objective.

To evaluate the usefulness of an adenosine triphosphate (ATP) bioluminescence assay for assessing the efficacy of daily hospital cleaning practices.

Design.

A 2-phase prospective intervention study.

Setting.

A university-affiliated community teaching hospital.

Methods.

During phase I of our study, 5 high-touch surfaces in 20 patient rooms were sampled before and after daily cleaning. Moistened swabs were used to sample these surfaces and were then plated onto routine and selective media, and aerobic colony counts were determined after 48 hours of incubation. Specialized ATP swabs were used to sample the same high-touch surfaces in the 20 patient rooms and were then placed in luminometers, and the amount of ATP present was expressed as relative light units. During phase II of our study, after in-service housekeeper educational sessions were given, the housekeepers were told in advance when ATP readings would be taken before and after cleaning.

Results.

During phase I, the colony counts revealed that the 5 high-touch surfaces were often not cleaned adequately. After cleaning, 24 (24%) of the 100 surface samples were still contaminated with methicillin-resistantStaphylococcus aureus, and 16 (16%) of the 100 surface samples still yielded vancomycin-resistant enterococci. ATP readings (expressed as relative light units) revealed that only bathroom grab bars and toilet seats were significantly cleaner after daily cleaning than before. During phase II, a total of 1,013 ATP readings were obtained before and after daily cleaning in 105 rooms. The median relative light unit was significantly lower (ie, surfaces were cleaner) after cleaning than before cleaning for all 5 high-touch surfaces.

Conclusions.

Suboptimal cleaning practices were documented by determining aerobic colony counts and by use of an ATP bioluminescence assay. ATP readings provided quantitative evidence of improved cleanliness of high-touch surfaces after the implementation of an intervention program.
A computational Grid framework for immunological applications
Authors: Halling-Brown Mark D. , Moss David S. , Sansom Clare E. , Shepherd Adrian J.
Published: June 2009

We have developed a computational Grid that enables us to exploit through a single interface a range of local, national and international resources. It insulates the user as far as possible from issues concerning administrative boundaries, passwords and different operating system features. This work has been undertaken as part of the European Union ImmunoGrid project whose aim is to develop simulations of the immune system at the molecular, cellular and organ levels. The ImmunoGrid consortium has members with computational resources on both sides of the Atlantic. By making extensive use of existing Grid middleware, our Grid has enabled us to exploit consortium and publicly available computers in a unified way, notwithstanding the diverse local software and administrative environments. We took 40 000 polypeptide sequences from 4000 avian and mammalian influenza strains and used a neural network for class I T-cell epitope prediction tools for 120 class I alleles and haplotypes to generate over 14 million high-quality protein–peptide binding predictions that we are mapping onto the three-dimensional structures of the proteins. By contrast, the Grid is also being used for developing new methods for class T-cell epitope predictions, where we have running batches of 120 molecular dynamics free-energy calculations.
Small heat-shock protein Hsp12 contributes to yeast tolerance to freezing stress
Authors: Pacheco A. , Pereira C. , Almeida M. J. , Sousa M. J.
Published: June 2009

TheHSP12gene encodes one of the two major small heat-shock proteins ofSaccharomyces cerevisiaeand is induced under different conditions, such as low and high temperatures, osmotic or oxidative stress and high sugar or ethanol concentrations. However, few studies could demonstrate any correlation betweenHSP12deletion or overexpression and a phenotype of sensitivity/resistance, making it difficult to attribute a role for Hsp12p under several of these stress conditions. We investigated the possible role of Hsp12p in yeast freezing tolerance. Contrary to what would be expected, thehsp12null mutant when subjected to prolonged storage at −20 °C showed an increased resistance to freezing when compared with the isogenic wild-type strain. Because the mutant strain displayed a higher intracellular trehalose concentration than the wild-type, which could mask the effect of manipulatingHSP12, we overexpressed theHSP12gene in a trehalose-6-phosphate synthase (TPS1) null mutant. Thetps1Δ strain overexpressingHSP12showed an increase in resistance to freezing storage, indicating that Hsp12p plays a role in freezing tolerance in a way that seems to be interchangeable with trehalose. In addition, we show that overexpression ofHSP12in thistps1Δ strain also increased resistance to heat shock and that absence ofHSP12compromises the ability of yeast cells to accumulate high levels of trehalose in response to a mild heat stress.
Phosphate and carbon source regulation of two PhoP-dependent glycerophosphodiester phosphodiesterase genes of Streptomyces coelicolor
Authors: Santos-Beneit Fernando , Rodríguez-García Antonio , Apel Alexander K. , Martín Juan F.
Published: June 2009

Glycerophosphodiesters are formed by deacylation of phospholipids.Streptomyces coelicolorand other soil-dwelling actinomycetes utilize glycerophosphodiesters as phosphate and carbon sources by the action of glycerophosphodiester phosphodiesterases (GDPDs). Seven genes encoding putative GDPDs occur in theS. coelicolorgenome. Two of these genes,glpQ1andglpQ2, encoding extracellular GDPDs, showed a PhoP-dependent upregulated profile in response to phosphate shiftdown. Expression studies using theluxABgenes as reporter confirmed the PhoP dependence of bothglpQ1andglpQ2. Footprinting analyses with pure GST-PhoP of theglpQ1promoter revealed four protected direct repeat units (DRu). PhoP binding affinity to theglpQ2promoter was lower and revealed a protected region containing five DRu. As expected forphoregulon genes, inorganic phosphate, and also glycerol 3-phosphate, inhibited the expression from bothglpQ1andglpQ2. The expression ofglpQ1was also repressed by serine and inositol but expression ofglpQ2was not. In contrast, glucose, fructose and glycerol increased expression ofglpQ2but not that ofglpQ1. In summary, our results suggest an interaction of phosphate control mediated by PhoP and carbon source regulation of theglpQ1andglpQ2genes involving complex operator structures.
Uptake of l-nicotine and of 6-hydroxy-l-nicotine by Arthrobacter nicotinovorans and by Escherichia coli is mediated by facilitated diffusion and not by passive diffusion or active transport
Authors: Ganas Petra , Brandsch Roderich
Published: June 2009

The mechanism by whichl-nicotine is taken up by bacteria that are able to grow on it is unknown. Nicotine degradation byArthrobacter nicotinovorans, a Gram-positive soil bacterium, is linked to the presence of the catabolic megaplasmid pAO1.l-[14C]Nicotine uptake assays withA. nicotinovoransshowed transport of nicotine across the cell membrane to be energy-independent and saturable with aKmof 6.2±0.1 μM and aVmaxof 0.70±0.08 μmol min−1(mg protein)−1. This is in accord with a mechanism of facilitated diffusion, driven by the nicotine concentration gradient. Nicotine uptake was coupled to its intracellular degradation, and anA. nicotinovoransstrain unable to degrade nicotine (pAO1−) showed no nicotine import. However, when the nicotine dehydrogenase genes were expressed in this strain, import ofl-[14C]nicotine took place.A. nicotinovoranspAO1−andEscherichia coliwere also unable to import 6-hydroxy-l-nicotine, but expression of the 6-hydroxy-l-nicotine oxidase gene allowed both bacteria to take up this compound.l-Nicotine uptake was inhibited byd-nicotine, 6-hydroxy-l-nicotine and 2-amino-l-nicotine, which may indicate transport of these nicotine derivatives by a common permease. Attempts to correlate nicotine uptake with pAO1 genes possessing similarity to amino acid transporters failed. In contrast to the situation at the blood–brain barrier, nicotine transport across the cell membrane by these bacteria was not by passive diffusion or active transport but by facilitated diffusion.
Severe Adverse Drug Reaction to Gadobenate Dimeglumine
Authors: Singer Benjamin D. , Woodrick Robert S. , Pedicano Jennifer B.
Published: May 2009

A 57-year-old man was admitted to our hospital for evaluation and management of stroke in the setting of an atrial septal defect. Shortly after receiving gadobenate dimeglumine for magnetic resonance imaging of the pelvic vessels, he experienced cardiac arrest from which he was resuscitated. His course was complicated by profound distributive shock. The presumed cause was a severe anaphylactic or anaphylactoid reaction to the gadolinium-based compound that he received.
Terminology of Lower Urinary Tract Symptoms. Helpful or Confusing ?
Authors: Vishwajit Sonia , Andersson Karl-Erik
Published: May 2009

An established standardized terminology is necessary for communication of scientific information, and for prevention of mistreatment and misdiagnosis. Terminology concerning the lower urinary tract has been much discussed; in particular, the meaning of terms like lower urinary tract symptoms (LUTS), urgency, frequency and nocturia, overactive bladder (OAB), and detrusor overactivity (DO). It is natural and desirable that all suggested definitions are subject to criticism, and it is important that discussions for improvement of the existing terminology continue.
Volatile Sampling from Biological Sources by the Closed-Loop-Stripping Technique
Authors: Kunert Maritta , David Anja , Becher Jana , Boland Wilhelm
Published: June 2009

INTRODUCTION

The closed-loop-stripping technique with absorber traps (e.g., charcoal, porous polymers) can be used to collect volatiles from different biological sources, for example, plants and insects. One notable advantage of the method is the high signal-to-noise ratio that can be achieved by continuous sampling of the volatiles from a producing source within a closed environment. The equipment required for the technique is inexpensive and can be easily adapted to the demands of the analyzed subject. Moreover, the system can be operated in the field since only air and a battery are needed. The volatiles can be recovered from the trap by thermodesorption or by elution with solvents. Solvent elution has the advantage that unknown compounds can be subjected to chemical transformations facilitating structure elucidation. Only very low amounts of solvents (20-40 μL) are needed to elute the microcarbon traps (1.5-5 mg). Single traps efficiently absorb volatiles up to the lower microgram range. Higher concentrations may result in insufficient trapping. In this protocol, we describe the collection of volatiles released from lima bean leaves (Phaseolus lunatus) after damage by feeding larvae of Spodoptera littoralis. The enclosed volume of air containing the emitted volatiles is circulated through miniature charcoal traps for 4 h or more. For analysis, the traps are eluted with dichloromethane.