bluuebunny/crossref_metadata_2025 huggingface dataset:
Three‐dimensional distribution of seismic anisotropy in the Hikurangi subduction zone beneath the central North Island, New Zealand
Authors: Eberhart‐Phillips Donna , Reyners Martin
Published: June 2009

We use earthquake arrival time data in the central North Island, New Zealand, in inversion for 3‐D Vp azimuthal anisotropy. It is parameterized with an isotropic component and two azimuthal anisotropy parameters for each node, and local earthquake shear wave splitting observations define the initial anisotropy model. Our results suggest that mantle flow, either within the mantle wedge or below the subducted slab, is not the primary source of anisotropy in the Hikurangi subduction zone. The largest region of anisotropy that we image is within the subducted slab, where anisotropy is consistently trench‐parallel and 5–9% magnitude from 32 to 185 km depth. Bending‐induced yielding in the slab offshore and as it passes through the trench provides an explanation for this slab anisotropy. Beneath the Taupo Volcanic Zone (TVZ), there is 1–4% trench‐normal anisotropy within 30 km of the surface of the slab, within a region entrained with motion of the slab. In contrast, only very weak (0–2%) anisotropy is imaged in the region of high‐temperature partial melt arising from active corner flow in the mantle wedge. In the crust geologic structure is important, with the largest crustal anisotropy (14%) related to schist. We image significant anisotropy aligned with the margins of the TVZ, related to extensive fracturing on the margins as the TVZ actively extends. Within the heavily intruded and underplated TVZ lower crust, the orientation of anisotropy switches to align with the extension direction. This orientation is consistent with other geophysical data suggesting the presence of connected melt in this region.
Variability of the Indian Ocean Dipole in coupled model paleoclimate simulations
Authors: Brown J. , Lynch A. H. , Marshall A. G.
Published: June 2009

The Indian Ocean Dipole (IOD) mode of variability has been observed to influence atmospheric circulation and precipitation over the Indian Ocean basin and surrounding continental areas, interacting with the Asian monsoon and El Niño Southern Oscillation (ENSO). Paleo‐IOD reconstructions from fossil corals from the eastern tropical Indian Ocean suggest that IOD events may have varied in strength and timing under past climate conditions. The variability of the IOD and interactions with the Asian monsoon and ENSO are investigated here using a series of coupled model simulations of time slices during the last 55,000 years. The Fast Ocean Atmosphere Model (FOAM) is used to simulate pre‐industrial climate and paleoclimate time slices at 6,000, 11,000, 21,000, 35,000, and 55,000 years before present. The strength and timing of IOD events in the FOAM simulations is found to vary, with larger amplitude IOD variability being associated with a weaker Asian summer monsoon and stronger ENSO variability. FOAM simulates a reduced strength IOD in the mid‐Holocene and stronger IOD variability in the Last Glacial Maximum time slice. There is some evidence that the timing of IOD events varies in response to changes in insolation seasonality over the tropical Indian Ocean and resulting changes in the timing and amplitude of the Asian summer monsoon and ENSO.
Diurnally driven scaling properties of Amazonian rainfall fields: Fourier spectra and order‐q statistical moments
Authors: Morales Julián E. , Poveda Germán
Published: June 2009

The influence of the diurnal cycle on spatial scaling properties of Amazonian rainfall fields is investigated using data gathered during the January–February 1999 Wet Season Atmospheric Meso‐scale Campaign in the state of Rondonia (Brazil, SW Amazonia). Most intense precipitation events with large spatial coverage occur during early afternoon. Amplitudes of average and maximum intensity diurnal cycles are higher during the easterly than during the westerly atmospheric regime. The diurnal cycle of average rainfall occupancy exhibits a significantly larger amplitude during the westerly regime. Storms exhibit power law Fourier spectra, E(k) = ck−β, with two scaling regimes characterized by different scaling exponents (β1 and β2), separated at a critical distance, which depends on the spatial extent of rainfall organization. Inversely correlated diurnal cycles for β1 and β2 reflect rainfall organization patterns at different spatial scales through the 24‐h period. The break occurs at smaller (larger) spatial scales during the morning (afternoon‐evening). Average values of c and β exhibit inversely related diurnal cycles, and different behavior during either atmospheric regime. Order‐q statistical moments indicate multiscaling of rainfall fields. Departures from simple scaling are also driven by the diurnal cycle, reflecting differences in convective activity and the spatial organization of rainfall throughout the 24‐h cycle. Departures from simple scaling are dependent on the moment order q. Clear‐cut differences between the estimated order‐q statistical moments appear during both atmospheric regimes. These results shed light toward linking physical processes with statistics in Amazonian storms.
Three‐dimensional simulation and inversion of borehole temperatures for reconstructing past climate in complex settings
Authors: Hopcroft Peter O. , Gallagher Kerry , Pain Christopher C. , Fang Fangxin
Published: June 2009

The majority of inversion methods used for inferring past ground surface temperatures (GST) from borehole temperature‐depth profiles rely on the assumption that heat flow is in the vertical direction only. This means that accounting for certain effects caused by the local terrain of a borehole is not possible and consequently, many borehole profiles cannot be used with confidence. Here, we describe a methodology to avoid this problem by solving the heat conduction forward problem in 3‐D using finite elements (FE). In order to make the inversion approach computationally tractable, we reduce the dimensions of this FE model using proper orthogonal decomposition. The inverse problem is cast in a probabilistic Bayesian framework for which the posterior probability distribution of the past GSTs is sampled using a reversible jump Markov chain Monte Carlo algorithm. This allows the resolution of the GST history over time to be explored by varying the parameterization of the GST model. Synthetic examples calculated with moderate topographies demonstrate the efficacy of the Bayesian 3‐D inversion method, and the results are compared with those using a 1‐D approach. For moderate topography, the latter can lead to spurious GST reconstructions. A further synthetic example demonstrates that the effect of incorrectly assuming lateral geological homogeneity is negligible. The inversion method is also compared with a more standard inversion method. A significant advantage of the Bayesian approach is that uncertainties in all of the model parameters can be accounted for, leading to a more realistic interpretation of the range of GST histories supported by the data. The methods presented here should allow a broader range of geothermal data to be used for paleoclimate reconstruction purposes in the future.
Future of Applied Watershed Science at Regional Scales
Authors: Benda Lee , Miller Daniel , Lanigan Steve , Reeves Gordon
Published: June 2009

The Internet‐driven evolution of communication and science technologies coincides with a parallel evolution in environmental policy and natural resource management. Resource managers must deal increasingly with land use and conservation plans applied at large spatial scales (watersheds, landscapes, states, regions) involving multiple interacting agencies and stakeholders. Many federal, state, and private organizations have similar objectives, questions, and data and analysis needs. This is motivating the development of community‐supported watershed databases and analysis systems of common structure and function across large geographic areas. Numerous state and regional analysis systems are targeting natural resource issues involving management of forests, freshwater fishes, wildlife, and water quality and supply.
Satellite Mission to Study Ocean Salinity and the Global Hydrological Cycle: 4th Aquarius/SAC‐D Science Workshop; Puerto Madryn, Argentina, 3–5 December 2008
Authors: Lagerloef Gary , Torrusio Sandra
Published: June 2009

Important aspects of climate change in the 21st century will involve interactions between ocean circulation and the global hydrological cycle, and their links to land surface hydrology, the cryosphere, the atmosphere, and other realms. The Aquarius'Satelite Aplicaciones Cientificas‐D (SAC‐D) satellite mission is a multidisciplinary observatory that will provide measurements of ocean salinity, ocean winds, rain, sea ice, land'sea surface temperatures, soil moisture, nighttime light sources, atmospheric temperature'humidity soundings, and the space environment, as well as autonomous data relay from remote ground stations. Scheduled for launch in May 2010, the project involves international contributions by Argentina, the United States, Italy, Canada, France, and Brazil, and has an active public awareness and education program (see http://www.conae.gov.ar/satelites/sac‐d.html and http://aquarius.gsfc.nasa.gov).
Largest Early Career Scientists Workshop on Polar Marine Research: IMPETUS 2008: Polar Observation and Monitoring; Saint Petersburg, Russia, 19–22 November 2008
Authors: Wegner Carolyn , Kassens Heidemarie
Published: June 2009

Eighty‐five young researchers from 20 countries met in Russia to learn about the latest techniques in polar ocean observation and monitoring and to discuss the advantages and limits of various techniques, methods of data transmission, and joint research projects. IMPETUS 2008, the largest workshop ever held for early career scientists in polar marine research, was organized by the Otto Schmidt Laboratory for Polar and Marine Research at the Arctic and Antarctic Research Institute, in Saint Petersburg; the Association of Polar Early Career Scientists; and the Permafrost Young Researchers Network.
Judy Holoviak Leaves AGU
Authors: Anonymous
Published: June 2009

Judy C. Holoviak, AGU director of publications, leaves AGU on 6 May 2009. Her nearly 45‐year career at AGU was recognized when she received the 2008 Edward A. Flinn III Award (see Eos, 89(52), 546, 2008).
Observing the Moon: The Modern Astronomer's Guide, Second Edition
Authors: Vickers Martin
Published: June 2009

Even before the ancient Greeks invented optical lenses, humans peered into the heavens with wonder. Notable figures such as Galileo and Isaac Newton are among the more famous astronomers who have helped humanity understand the solar system and our place within it. The study of the Moon has enhanced our understanding of the solar system, including our own planet. The Moon, in addition to being a fascinating feature in the night sky, has prompted great works of art and literature the world over.
Light elements and Li isotopes across the northern portion of the Central American subduction zone
Authors: Walker James A. , Teipel Alexa P. , Ryan Jeffrey G. , Syracuse Ellen
Published: June 2009

Quaternary mafic rocks have been erupted from volcanoes both on and behind the volcanic front in southeastern Guatemala and western El Salvador. Behind‐the‐front volcanism extends almost continuously some 110 km from the front. B and Li contents, as well as B/Nb and Li/Yb ratios, are generally higher in the mafic volcanic rocks of the volcanic front and lower in those behind the front. Beryllium concentrations show the opposite relationships, with generally higher values behind the front. In addition, many behind‐the‐front samples have lower δ7Li (2–3‰ versus 4–6‰ for the volcanic front). Guatemalan volcanic rocks, in general, have lower δ7Li than those found along the remainder of the Central American margin. The light element variations across northern Central America clearly indicate that the volcanic front receives a much more pronounced fluid contribution from dehydrating, subducting Cocos lithosphere than the behind‐the‐front region. This dehydration pulse occurs at slab depths between 85 and 105 km, and selective enrichments of B, Cs, and Cl in volcanic rocks of the volcanic front suggest that the source of this pulse is dehydrating serpentinite. In addition, the dehydration pulse from subducted serpentinite is likely superimposed on a continuous dehydration signal provided by subducting oceanic crust which continues behind the volcanic front to slab depths >200 km. The enhanced fluid contributions at the front produce higher degrees of wedge melting, thus explaining the lower Be contents of front samples. There are two possible explanations of the lower δ7Li of many behind‐the‐front volcanic rocks from southeastern Guatemala/western El Salvador: selective loss of 7Li during progressive dehydration of subducting Cocos lithosphere or diffusive fractionation accompanying late stage, selective crustal contamination. Since the slightly lower δ7Li of Guatemalan volcanic rocks in general is consistent with a minor crustal overprint, the second explanation is favored and could be relevant to the few subduction zones where lower Li isotopic values characterize back‐arc regions. Light element variation across southeastern Guatemala and western El Salvador is consistent with the operation of decompression melting behind the volcanic front. Be/Zr ratios across the northern portion of the Central American subduction zone may indicate some mobility of Be.
Can magnetotail reconnection produce the auroral intensities observed in the conjugate ionosphere?
Authors: Østgaard N. , Snekvik K. , Borg A. L. , Åsnes A. , Pedersen A. , Øieroset M. , Phan T. , Haaland S. E.
Published: June 2009

In a recent case study, Borg et al. (2007) reported that an inverted V structure, caused by a field‐aligned potential drop of 30 kV producing very strong X‐ray aurora, was found in connection with tail reconnection. However, the in situ particle measurements indicated clearly that the particles responsible for the X‐ray aurora were not accelerated by the reconnection process. In this article, we report the predicted auroral intensities of thirteen reconnection events where Cluster passed through the reconnection region. For six of the events, global auroral imaging data were available and the predicted auroral intensities could be compared with the observed intensities. Our main findings are as follows: (1) Acceleration in the reconnection region is generally not sufficient to account for the observed auroral intensities. (2) Additional acceleration between the reconnection region and the ionosphere is needed to explain the auroral intensities. Although we see signatures that point toward potential drops at the flanks of bursty bulk flows (BBFs), we also find signatures of Alfvén wave accelerated electrons at 700 km and we are not able to determine the most likely acceleration mechanism. (3) The reconnection events are observed 2–14 min after substorm onset and indicate that reconnection is an expanding process observed along the poleward boundary of the aurora.
Viscosity of liquid ferric sulfate solutions and application to the formation of gullies on Mars
Authors: Chevrier Vincent F. , Ulrich Richard , Altheide Travis S.
Published: June 2009

We studied the viscosity of ferric sulfate Fe2(SO4)3 solutions as a model for low‐temperature liquids on the surface of Mars and their implication in the formation of gullies. Viscosity varies with temperature and concentration, ranging from 7.0 × 10−3 Pa s for 38.8 wt % at 285.15 K to 4.6 Pa s for 58.2 wt % at 260.15 K. Using the experimental results, we built a semiempirical equation of viscosity as a function of temperature and salt concentration, which was combined with a numerical model to estimate the effect of these solutions on the formation of gullies. Calculated fluid velocities ranged from 0.5 to 14 m s−1, in accordance with estimates from image analyses. Turbulent flow occurs in the majority of the conditions and is characterized by a constant velocity (∼8.5 m s−1). At very low temperature and high concentration, the laminar regime shows reduced velocities (down to ∼0.5 m s−1). In between, a transitional regime presents high velocities, up to 14 m s−1. Using the velocities, we determined the size threshold for boulders to be moved by the liquid flow. Depending on the regime, boulders of diameter inferior to 3 m (turbulent), 4 m (transition), and down to 0.5 m (laminar) are displaced. Since laminar flow occurs only in an extremely limited range of conditions, for low temperatures (<240 K) and supersaturated solutions, the abundance of small boulders (∼0.5 m) in gully channels requires lower velocities and higher viscosities than ferric sulfate solution or any other water‐based liquid can reach. This suggests an important participation of debris mixed with the liquid phase.
NCU-G1 is a highly glycosylated integral membrane protein of the lysosome
Authors: Schieweck Oliver , Damme Markus , Schröder Bernd , Hasilik Andrej , Schmidt Bernhard , Lübke Torben
Published: June 2009

Until recently, a modest number of approx. 40 lysosomal membrane proteins had been identified and even fewer were characterized in their function. In a proteomic study, using lysosomal membranes from human placenta we identified several candidate lysosomal membrane proteins and proved the lysosomal localization of two of them. In the present study, we demonstrate the lysosomal localization of the mouse orthologue of the human C1orf85 protein, which has been termed kidney-predominant protein NCU-G1 (GenBank® accession number: AB027141). NCU-G1 encodes a 404 amino acid protein with a calculated molecular mass of 39 kDa. The bioinformatics analysis of its amino acid sequence suggests it is a type I transmembrane protein containing a single tyrosine-based consensus lysosomal sorting motif at position 400 within the 12-residue C-terminal tail. Its lysosomal localization was confirmed using immunofluorescence with a C-terminally His-tagged NCU-G1 and the lysosomal marker LAMP-1 (lysosome-associated membrane protein-1) as a reference, and by subcellular fractionation of mouse liver after a tyloxapol-induced density shift of the lysosomal fraction using an anti-NCU-G1 antiserum. In transiently transfected HT1080 and HeLa cells, the His-tagged NCU-G1 was detected in two molecular forms with apparent protein sizes of 70 and 80 kDa, and in mouse liver the endogenous wild-type NCU-G1 was detected as a 75 kDa protein. The remarkable difference between the apparent and the calculated molecular masses of NCU-G1 was shown, by digesting the protein with N-glycosidase F, to be due to an extensive glycosylation. The lysosomal localization was impaired by mutational replacement of an alanine residue for the tyrosine residue within the putative sorting motif.
Salt and high blood pressure
Authors: Mohan Sailesh , Campbell Norm R. C.
Published: June 2009

HBP (high blood pressure) is the leading risk of death in the world. Unfortunately around the world, blood pressure levels are predicted to become even higher, especially in developing countries. High dietary salt is an important contributor to increased blood pressure. The present review evaluates the association between excess dietary salt intake and the importance of a population-based strategy to lower dietary salt, and also highlights some salt-reduction strategies from selected countries. Evidence from diverse sources spanning animal, epidemiology and human intervention studies demonstrate the association between salt intake and HBP. Furthermore, animal studies indicate that short-term interventions in humans may underestimate the health risks associated with high dietary sodium. Recent intervention studies have found decreases in cardiovascular events following reductions in dietary sodium. Salt intake is high in most countries and, therefore, strategies to lower salt intake could be an effective means to reduce the increasing burden of HBP and the associated cardiovascular disease. Effective collaborative partnerships between governments, the food industry, scientific organizations and healthcare organizations are essential to achieve the WHO (World Health Organization)-recommended population-wide decrease in salt consumption to less than 5 g/day. In the milieu of increasing cardiovascular disease worldwide, particularly in resource-constrained low- and middle-income countries, salt reduction is one of the most cost-effective strategies to combat the epidemic of HBP, associated cardiovascular disease and improve population health.
Reduction of root flavonoid level and its potential involvement in lateral root emergence in Arabidopsis thaliana grown under low phosphate supply
Authors: Yang Huixia , Liu Hong , Li Gang , Feng Juanjuan , Qin Huanju , Liu Xin , Xue Hongwei , Wang Daowen
Published: June 2009

Although it is well known that phosphate (Pi) deficiency affects flavonoid accumulation in higher plants, knowledge on the regulation and potential function of flavonoids in the plants grown with low Pi supply is lacking. In this work, we found that low Pi treatment caused significant reduction of root flavonoid (e.g. quercetin, kaempferol and their derivatives) levels in both Columbia (Col-0) and Landsberg erecta (Ler) ecotypes of Arabidopsis thaliana (L.) Heynh. Further investigations revealed that the dysfunction of PHR1, PHO1, PHO2 and NPC4 did not affect the decrease of root flavonoid level by low Pi treatment. In contrast, pldζ2, a knockout mutant of the Arabidopsis phospholipase Dζ2, exhibited defects in the reduction of root flavonoid level and lateral root (LR) emergence under low Pi conditions. When grown under low Pi supply, the transport of auxin from the shoot apex into the root, expression of the auxin responsive DR5::GUS marker and induction of the auxin responsive genes were all significantly less efficient in pldζ2 than in wild-type (WT) control. This is the first report on the reduction of root flavonoid level and its likely contribution to increased LR emergence in Arabidopsis under Pi deficiency conditions, which may facilitate the adaptation of plants to the growth environments with poor Pi availability.
Testing the efficacy of a boundary fence at an important tropical seabird breeding colony and key tourist destination
Authors: Devney Carol A. , Congdon Bradley C.
Published: June 2009

Tourists have the potential to detrimentally impact breeding seabirds, particularly at popular destinations such as on the Great Barrier Reef. Michaelmas Cay is a significant seabird rookery and prime tourist destination on the reef. In 1990, Queensland Parks & Wildlife Service erected a fence to separate tourists from fragile nesting habitat. We used two independent assessments during different breeding seasons to determine the potential impacts of tourism on two pelagic seabird species breeding on the cay. In the first quasi-experiment, egg losses by sooty terns (Sterna fuscata) and common noddies (Anous stolidus) were monitored at four distances (3, 6, 18 and 36 m) from a tourist enclosure. Our second quasi-experiment involved monitoring adult provisioning rates, chick growth and chick survival of sooty terns at two locations, one adjacent to the tourist fence and one 50 m away. At plots 3–6 m from the fence, we observed higher among-week variation in egg loss but no differences in total egg loss as compared with the more distant plots. The only difference observed between plots during our second quasi-experiment was that nest predation was higher at the tourist fence plot. Our research suggests that as long as the effects observed do not influence post-fledging survival or gull predation does not impact under different conditions, current management protocols are appropriately facilitating shared usage between wildlife and the tourism industry at Michaelmas Cay.
Longevity of DayGlo fluorescent particle marker used to mark birds in flight pen and field
Authors: Tupper Shelagh K. , Cummings John L. , Engeman Richard M.
Published: June 2009

Spray application of fluorescent particles is a widely used and very valuable technique for marking birds. This remains one of the few practical means to mark large numbers of birds for monitoring movement, despite recent availability of a variety of more technologically advanced options. We monitored the longevity of the DayGlo fluorescent particle marker on red-winged blackbirds under simulated field conditions in a flight pen, and in an observational field experiment. In the pen study we banded 52 red-winged blackbirds with individually numbered leg bands, and sprayed them with DayGlo fluorescent particle marker from a distance of ~50 cm, on 1 December 2004. These birds were recaptured and DayGlo fluorescent particle marks assessed 11 times until 10 August 2005. All 31 surviving birds at the conclusion of the study (i.e. after 254 days) retained at least some DayGlo fluorescent particle marker on one or more body regions. Wings retained DayGlo fluorescent particle marks longer than other body regions and thus could be used to identify marks in large-scale collections. Roosting wild blackbirds aerially marked in September and October 2005 retained marks through June 2006, 263 days after marking. The formulation used is inexpensive (US$4.00 L−1), easy-to-apply at many scales and practical for many species (e.g. starlings, blackbirds, sparrows, gulls and shorebirds).
Atmospheric pressure as a natural climate regulator for a terrestrial planet with a biosphere
Authors: Li King-Fai , Pahlevan Kaveh , Kirschvink Joseph L. , Yung Yuk L.
Published: June 2009

Lovelock and Whitfield suggested in 1982 that, as the luminosity of the Sun increases over its life cycle, biologically enhanced silicate weathering is able to reduce the concentration of atmospheric carbon dioxide (CO
2
) so that the Earth's surface temperature is maintained within an inhabitable range. As this process continues, however, between 100 and 900 million years (Ma) from now the CO
2
concentration will reach levels too low for C
3
and C
4
photosynthesis, signaling the end of the solar-powered biosphere. Here, we show that atmospheric pressure is another factor that adjusts the global temperature by broadening infrared absorption lines of greenhouse gases. A simple model including the reduction of atmospheric pressure suggests that the life span of the biosphere can be extended at least 2.3 Ga into the future, more than doubling previous estimates. This has important implications for seeking extraterrestrial life in the Universe. Space observations in the infrared region could test the hypothesis that atmospheric pressure regulates the surface temperature on extrasolar planets.
A Müllerian mimicry ring in Appalachian millipedes
Authors: Marek Paul E. , Bond Jason E.
Published: June 2009

Few biological phenomena provide such an elegant and straightforward example of evolution by natural selection as color mimicry among unrelated organisms. By mimicking the appearance of a heavily defended aposematic species, members of a second species gain protection from predators and, potentially, enhanced fitness. Mimicking a preexisting warning advertisement is economical because a potentially costly novel one can be avoided; simultaneously, the addition of more aposematic individuals enhances the overall warning effect. The better-known mimetic systems comprise tropical taxa, but here, we show a remarkable example of color mimicry in 7 species of blind, cyanide-generating millipedes endemic to the Appalachian Mountains of temperate North America. Because these millipedes lack eyes, there is no sexual selection or intraspecific signaling for coloration, providing an ideal system for mimicry studies. We document a Müllerian symbiosis where unrelated species vary in color and pattern over geographical space but appear identical where they co-occur. By using spectral color data, estimations of evolutionary history, and detailed field observations of species abundance, we test 4 predictions of Müllerian mimicry theory and begin to unravel the story of an elaborate mimetic diversification in the forests of Appalachia.
A unique Middle Miocene European hominoid and the origins of the great ape and human clade
Authors: Moyà-Solà Salvador , Alba David M. , Almécija Sergio , Casanovas-Vilar Isaac , Köhler Meike , De Esteban-Trivigno Soledad , Robles Josep M. , Galindo Jordi , Fortuny Josep
Published: June 2009

The great ape and human clade (Primates: Hominidae) currently includes orangutans, gorillas, chimpanzees, bonobos, and humans. When, where, and from which taxon hominids evolved are among the most exciting questions yet to be resolved. Within the Afropithecidae, the Kenyapithecinae (Kenyapithecini + Equatorini) have been proposed as the sister taxon of hominids, but thus far the fragmentary and scarce Middle Miocene fossil record has hampered testing this hypothesis. Here we describe a male partial face with mandible of a previously undescribed fossil hominid,
Anoiapithecus brevirostris
gen. et sp. nov., from the Middle Miocene (11.9 Ma) of Spain, which enables testing this hypothesis. Morphological and geometric morphometrics analyses of this material show a unique facial pattern for hominoids. This taxon combines autapomorphic features—such as a strongly reduced facial prognathism—with kenyapithecine (more specifically, kenyapithecin) and hominid synapomorphies. This combination supports a sister-group relationship between kenyapithecins (
Griphopithecus
+
Kenyapithecus
) and hominids. The presence of both groups in Eurasia during the Middle Miocene and the retention in kenyapithecins of a primitive hominoid postcranial body plan support a Eurasian origin of the Hominidae. Alternatively, the two extant hominid clades (Homininae and Ponginae) might have independently evolved in Africa and Eurasia from an ancestral, Middle Miocene stock, so that the supposed crown-hominid synapomorphies might be homoplastic.
The porin OmpD from nontyphoidal
Salmonella
is a key target for a protective B1b cell antibody response
Authors: Gil-Cruz Cristina , Bobat Saeeda , Marshall Jennifer L. , Kingsley Robert A. , Ross Ewan A. , Henderson Ian R. , Leyton Denisse L. , Coughlan Ruth E. , Khan Mahmood , Jensen Karina T. , Buckley Christopher D. , Dougan Gordon , MacLennan Ian C. M. , López-Macías Constantino , Cunningham Adam F.
Published: June 2009

Invasive nontyphoidal
Salmonella
(NTS), including
Salmonella typhimurium
(STm), are major yet poorly-recognized killers of infants in sub-Saharan Africa. Death in these children is usually associated with bacteremia, commonly in the absence of gastrointestinal symptoms. Evidence from humans and animal studies suggest that severe infection and bacteremia occur when specific Ab is lacking. Understanding how Ab responses to
Salmonella
are regulated will help develop vaccines against these devastating infections. STm induces atypical Ab responses characterized by prominent, accelerated, extrafollicular T-independent (TI) Ab against a range of surface antigens. These responses develop without concomitant germinal centers, which only appear as infection resolves. Here, we show STm rapidly induces a population of TI B220
+
CD5
−
B1b cells during infection and TI Ab from B1b cells targets the outer membrane protein (Omp) porins OmpC, OmpD and OmpF but not flagellin. When porins are used as immunogens they can ablate bacteremia and provide equivalent protection against STm as killed bacterial vaccine and this is wholly B cell-dependent. Furthermore Ab from porin-immunized chimeras, that have B1b cells, is sufficient to impair infection. Infecting with porin-deficient bacteria identifies OmpD, a protein absent from
Salmonella
Typhi, as a key target of Ab in these infections. This work broadens the recognized repertoire of TI protein antigens and highlights the importance of Ab from different B cell subsets in controlling STm infection. OmpD is a strong candidate vaccine target and may, in part, explain the lack of cross-protection between
Salmonella
Typhi and STm infections.
Temperature sensitivity of human perforin mutants unmasks subtotal loss of cytotoxicity, delayed FHL, and a predisposition to cancer
Authors: Chia Jenny , Yeo Kim Pin , Whisstock James C. , Dunstone Michelle A. , Trapani Joseph A. , Voskoboinik Ilia
Published: June 2009

The pore-forming protein perforin is critical for defense against many human pathogens and for preventing a catastrophic collapse of immune homeostasis, manifested in infancy as Type 2 familial hemophagocytic lymphohistiocytosis (FHL). However, no evidence has yet linked defective perforin cytotoxicity with cancer susceptibility in humans. Here, we examined perforin function in every patient reported in the literature who lived to at least 10 years of age without developing FHL despite inheriting mutations in both of their perforin (
PRF1
) alleles. Our analysis showed that almost 50% of these patients developed at least 1 hematological malignancy in childhood or adolescence. The broad range of pathologies argued strongly against a common environmental or viral cause for the extraordinary cancer incidence. Functionally, what distinguished these patients was their inheritance of
PRF1
alleles encoding temperature-sensitive missense mutations. By contrast, truly null missense mutations with no rescue at the permissive temperature were associated with the more common severe presentation with FHL in early infancy. Our study provides the first mechanistic evidence for a link between defective perforin-mediated cytotoxicity and cancer susceptibility in humans and establishes the paradigm that temperature sensitivity of perforin function is a predictor of FHL severity.
Cholera toxin inhibits IL-12 production and CD8α+ dendritic cell differentiation by cAMP-mediated inhibition of IRF8 function
Authors: la Sala Andrea , He Jianping , Laricchia-Robbio Leopoldo , Gorini Stefania , Iwasaki Akiko , Braun Michael , Yap George S. , Sher Alan , Ozato Keiko , Kelsall Brian
Published: June 2009

Prior studies have demonstrated that cholera toxin (CT) and other cAMP-inducing factors inhibit interleukin (IL)-12 production from monocytes and dendritic cells (DCs). We show that CT inhibits Th1 responses in vivo in mice infected with Toxoplasma gondii. This correlated with low serum IL-12 levels and a selective reduction in the numbers of CD8α+ conventional DCs (cDCs) in lymphoid organs. CT inhibited the function of interferon (IFN) regulatory factor (IRF) 8, a transcription factor known to positively regulate IL-12p35 and p40 gene expression, and the differentiation of CD8α+ and plasmacytoid DCs (pDCs). Fluorescence recovery after photobleaching analysis showed that exposure to CT, forskolin, or dibutyryl (db) cAMP blocked LPS and IFN-γ–induced IRF8 binding to chromatin. Moreover, CT and dbcAMP inhibited the binding of IRF8 to the IFN-stimulated response element (ISRE)–like element in the mouse IL-12p40 promoter, likely by blocking the formation of ISRE-binding IRF1–IRF8 heterocomplexes. Furthermore, CT inhibited the differentiation of pDCs from fms-like tyrosine kinase 3 ligand–treated bone marrow cells in vitro. Therefore, because IRF8 is essential for IL-12 production and the differentiation of CD8α+ cDCs and pDCs, these data suggest that CT and other Gs-protein agonists can affect IL-12 production and DC differentiation via a common mechanism involving IRF8.
CD95 co-stimulation blocks activation of naive T cells by inhibiting T cell receptor signaling
Authors: Strauss Gudrun , Lindquist Jonathan A. , Arhel Nathalie , Felder Edward , Karl Sabine , Haas Tobias L. , Fulda Simone , Walczak Henning , Kirchhoff Frank , Debatin Klaus-Michael
Published: June 2009

CD95 is a multifunctional receptor that induces cell death or proliferation depending on the signal, cell type, and cellular context. Here, we describe a thus far unknown function of CD95 as a silencer of T cell activation. Naive human T cells triggered by antigen-presenting cells expressing a membrane-bound form of CD95 ligand (CD95L) or stimulated by anti-CD3 and -CD28 antibodies in the presence of recombinant CD95L had reduced activation and proliferation, whereas preactivated, CD95-sensitive T cells underwent apoptosis. Triggering of CD95 during T cell priming interfered with proximal T cell receptor signaling by inhibiting the recruitment of ζ-chain–associated protein of 70 kD, phospholipase-γ, and protein kinase C-θ into lipid rafts, thereby preventing their mutual tyrosine protein phosphorylation. Subsequently, Ca2+ mobilization and nuclear translocation of transcription factors NFAT, AP1, and NF-κB were strongly reduced, leading to impaired cytokine secretion. CD95-mediated inhibition of proliferation in naive T cells could not be reverted by the addition of exogenous interleukin-2 and T cells primed by CD95 co-stimulation remained partially unresponsive upon secondary T cell stimulation. HIV infection induced CD95L expression in primary human antigeen-presenting cells, and thereby suppressed T cell activation, suggesting that CD95/CD95L-mediated silencing of T cell activation represents a novel mechanism of immune evasion.
Spontaneous relapsing-remitting EAE in the SJL/J mouse: MOG-reactive transgenic T cells recruit endogenous MOG-specific B cells
Authors: Pöllinger Bernadette , Krishnamoorthy Gurumoorthy , Berer Kerstin , Lassmann Hans , Bösl Michael R. , Dunn Robert , Domingues Helena S. , Holz Andreas , Kurschus Florian C. , Wekerle Hartmut
Published: June 2009

We describe new T cell receptor (TCR) transgenic mice (relapsing-remitting [RR] mice) carrying a TCR specific for myelin oligodendrocyte glycoprotein (MOG) peptide 92–106 in the context of I-As. Backcrossed to the SJL/J background, most RR mice spontaneously develop RR experimental autoimmune encephalomyelitis (EAE) with episodes often altering between different central nervous system tissues like the cerebellum, optic nerve, and spinal cord. Development of spontaneous EAE depends on the presence of an intact B cell compartment and on the expression of MOG autoantigen. There is no spontaneous EAE development in B cell–depleted mice or in transgenic mice lacking MOG. Transgenic T cells seem to expand MOG autoreactive B cells from the endogenous repertoire. The expanded autoreactive B cells produce autoantibodies binding to a conformational epitope on the native MOG protein while ignoring the T cell target peptide. The secreted autoantibodies are pathogenic, enhancing demyelinating EAE episodes. RR mice constitute the first spontaneous animal model for the most common form of multiple sclerosis (MS), RR MS.
Genetic identity, biological phenotype, and evolutionary pathways of transmitted/founder viruses in acute and early HIV-1 infection
Authors: Salazar-Gonzalez Jesus F. , Salazar Maria G. , Keele Brandon F. , Learn Gerald H. , Giorgi Elena E. , Li Hui , Decker Julie M. , Wang Shuyi , Baalwa Joshua , Kraus Matthias H. , Parrish Nicholas F. , Shaw Katharina S. , Guffey M. Brad , Bar Katharine J. , Davis Katie L. , Ochsenbauer-Jambor Christina , Kappes John C. , Saag Michael S. , Cohen Myron S. , Mulenga Joseph , Derdeyn Cynthia A. , Allen Susan , Hunter Eric , Markowitz Martin , Hraber Peter , Perelson Alan S. , Bhattacharya Tanmoy , Haynes Barton F. , Korber Bette T. , Hahn Beatrice H. , Shaw George M.
Published: June 2009

Identification of full-length transmitted HIV-1 genomes could be instrumental in HIV-1 pathogenesis, microbicide, and vaccine research by enabling the direct analysis of those viruses actually responsible for productive clinical infection. We show in 12 acutely infected subjects (9 clade B and 3 clade C) that complete HIV-1 genomes of transmitted/founder viruses can be inferred by single genome amplification and sequencing of plasma virion RNA. This allowed for the molecular cloning and biological analysis of transmitted/founder viruses and a comprehensive genome-wide assessment of the genetic imprint left on the evolving virus quasispecies by a composite of host selection pressures. Transmitted viruses encoded intact canonical genes (gag-pol-vif-vpr-tat-rev-vpu-env-nef) and replicated efficiently in primary human CD4+ T lymphocytes but much less so in monocyte-derived macrophages. Transmitted viruses were CD4 and CCR5 tropic and demonstrated concealment of coreceptor binding surfaces of the envelope bridging sheet and variable loop 3. 2 mo after infection, transmitted/founder viruses in three subjects were nearly completely replaced by viruses differing at two to five highly selected genomic loci; by 12–20 mo, viruses exhibited concentrated mutations at 17–34 discrete locations. These findings reveal viral properties associated with mucosal HIV-1 transmission and a limited set of rapidly evolving adaptive mutations driven primarily, but not exclusively, by early cytotoxic T cell responses.
Factorial Design for Improving Influenza Vaccination Among Employees of a Large Health System
Authors: Zimmerman Richard Kent , Nowalk Mary Patricia , Lin Chyongchiou J. , Raymund Mahlon , Fox Dwight E. , Harper Jay D. , Tanis Mark D. , Willis Bayo C.
Published: June 2009

Objective.

As healthcare personnel (HCP) influenza vaccination becomes a quality indicator for healthcare facilities, effective inter¬ventions are needed. This study was designed to test a factorial design to improve HCP vaccination rates.

Design.

A before-after trial with education, publicity, and free and easily accessible influenza vaccines used a factorial design to determine the effect of mobile vaccination carts and incentives on vaccination rates of HCP, who were divided into groups on the basis of their level of patient contact (ie, business and/or administrative role, indirect patient contact, and direct patient contact).

Setting.

Eleven acute care facilities in a large health system.

Participants.

More than 26,000 nonphysician employees.

Results.

Influenza vaccination rates increased significantly in most facilities and increased system-wide from 32.4% to 39.6% (P < .001). In the baseline year, business unit employee vaccination rates were significantly higher than among HCP with patient contact; rates did not differ significantly across groups in the intervention year. In logistic regression that accounted for demographic characteristics, intervention year, and other factors, the use of incentives and/or mobile carts that provided access to vaccine at the work unit significantly increased the likelihood of vaccination among HCP with direct and indirect patient contact, compared with control sites.

Conclusions.

Interventions to improve vaccination rates are differentially effective among HCP with varying levels of patient contact. Mobile carts appear to remove access barriers, whereas incentives may motivate HCP to be vaccinated. Education and publicity may be sufficient for workers in business or administrative positions. Interventions tailored by worker type are likely to be most successful for improving HCP vaccination rates.
Constraints on evolution of virus avirulence factors predict the durability of corresponding plant resistances
Authors: JANZAC BERENGER , FABRE FREDERIC , PALLOIX ALAIN , MOURY BENOIT
Published: June 2009

Understanding the factors driving pathogen emergence and re‐emergence is a major challenge, particularly in agriculture, where the use of resistant plant cultivars imposes strong selective pressures on plant pathogen populations and leads frequently to ‘resistance breakdown’. Presently, durable resistances are only identified after a long period of large‐scale cultivation of resistant cultivars. We propose a new predictor of the durability of plant resistance. Because resistance breakdown involves modifications in the avirulence factors of pathogens, we tested for correlations between the evolutionary constraints acting on avirulence factors or their diversity and the durability of the corresponding resistance genes in the case of plant–virus interactions. An analysis performed on 20 virus species–resistance gene combinations revealed that the selective constraints applied on amino acid substitutions in virus avirulence factors correlate with the observed durability of the corresponding resistance genes. On the basis of this result, a model predicting the potential durability of resistance genes as a function of the selective constraints applied on the corresponding avirulence factors is proposed to help breeders to select the most durable resistance genes.
Aldosterone glucuronidation by human liver and kidney microsomes and recombinant UDP‐glucuronosyltransferases: Inhibition by NSAIDs
Authors: Knights Kathleen M. , Winner Leanne K. , Elliot David J. , Bowalgaha Kushari , Miners John O.
Published: June 2009

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Carboxylic acid NSAIDs are extensively glucuronidated as either the parent drug or hydroxylated metabolites and UGT2B7 is ranked highest in terms of NSAID‐glucuronidation activity.

• NSAIDs cause adverse renal effects including sodium and water retention and hyperkalaemia.

• In human kidney the mineralocorticoid aldosterone is glucuronidated directly to form aldosterone 18β‐glucuronide.

WHAT THIS STUDY ADDS

• Human liver and kidney microsomes and UGT1A10 and UGT2B7 catalyze aldosterone18β‐glucuronidation.

• Non‐selective NSAIDs inhibit renal and hepatic aldosterone18β‐glucuronidation andin vivothis may lead to elevated intra‐renal concentrations of this hormone.

• Common involvement of UGT2B7 in NSAID and aldosterone glucuronidation predicates an intra‐renal NSAID‐aldosterone interaction that may explain in part the clinical observations of variable effects of NSAIDs on electrolytes, fluid retention and blood pressure.

AIMS

To characterize: i) the kinetics of aldosterone (ALDO) 18β‐glucuronidation using human liver and human kidney microsomes and identify the human UGT enzyme(s) responsible for ALDO 18β‐glucuronidation and ii) the inhibition of ALDO 18β‐glucuronidation by non‐selective NSAIDs.

METHODS

Using HPLC and LC‐MS methods, ALDO 18β‐glucuronidation was characterized using human liver (n= 6), human kidney microsomes (n= 5) and recombinant human UGT 1A1, 1A3, 1A4, 1A5, 1A6, 1A7, 1A8, 1A9, 1A10, 2B4, 2B7, 2B10, 2B15, 2B17 and 2B28 as the enzyme sources. Inhibition of ALDO 18β‐glucuronidation was investigated using alclofenac, cicloprofen, diclofenac, diflunisal, fenoprofen,R‐ andS‐ibuprofen, indomethacin, ketoprofen, ketorolac, meclofenamic acid, mefenamic acid,S‐naproxen, pirprofen and tiaprofenic acid. A rank order of inhibition (IC50) was established and the mechanism of inhibition investigated using diclofenac,S‐ibuprofen, indomethacin, mefenamic acid andS‐naproxen.

RESULTS

ALDO 18β‐glucuronidation by hepatic and renal microsomes exhibited Michaelis‐Menten kinetics. Mean (±SD)Km,Vmaxand CLintvalues for HLM and HKCM were 509 ± 137 and 367 ± 170 µm, 1075 ± 429 and 1110 ± 522 pmol min−1 mg−1, and 2.36 ± 1.12 and 3.91 ± 2.35 µl min−1 mg−1, respectively. Of the UGT proteins, only UGT1A10 and UGT2B7 converted ALDO to its 18β‐glucuronide. All NSAIDs investigated inhibited ALDO 18β‐G formation by HLM, HKCM and UGT2B7. The rank order of inhibition (IC50) of renal and hepatic ALDO 18β‐glucuronidation followed the general trend: fenamates > diclofenac > arylpropionates.

CONCLUSION

A NSAID‐ALDO interactionin vivomay result in elevated intra‐renal concentrations of ALDO that may contribute to the adverse renal effects of NSAIDs and their effects on antihypertensive drug response.