Emerging tools to study proteoglycan function during skeletal development.

In the past 20years, appreciation for the varied roles of proteoglycans (PGs), which are specific types of sugar-coated proteins, has increased dramatically. PGs in the extracellular matrix were long known to impart structural functions to many tissues, especially articular cartilage, which cushions bones and allows mobility at skeletal joints. Indeed, osteoarthritis is a debilitating disease associated with loss of PGs in articular cartilage. Today, however, PGs have a demonstrated role in cell biological processes, such as growth factor signalling, prompting new perspectives on the etiology of PG-associated diseases. Here, we review diseases associated with defects in PG synthesis and sulfation, also highlighting current understanding of the underlying genetics, biochemistry, and cell biology. Since most research has analyzed a class of PGs called heparan sulfate PGs, more attention is paid here to studies of chondroitin sulfate PGs (CSPGs), which are abundant in cartilage. Interestingly, CSPG synthesis is tightly linked to the cell biological processes of secretion and lysosomal degradation, suggesting that these systems may be linked genetically. Animal models of loss of CSPG function have revealed CSPGs to impact skeletal development. Specifically, our work from a mutagenesis screen in zebrafish led to the hypothesis that cartilage PGs normally delay the timing of endochondral ossification. Finally, we outline emerging approaches in zebrafish that may revolutionize the study of cartilage PG function, including transgenic methods and novel imaging techniques. Our recent work with X-ray fluorescent imaging, for example, enables direct correlation of PG function with PG-dependent biological processes.

Dietary competition between the alien Asian Musk Shrew (Suncus murinus) and a re-introduced population of Telfair's Skink (Leiolopisma telfairii).

Re-introduction of rare species to parts of their historical range is becoming increasingly important as a conservation strategy. Telfair's Skinks (Leiolopisma telfairii), once widespread on Mauritius, were until recently found only on Round Island. There it is vulnerable to stochastic events, including the introduction of alien predators that may either prey upon it or compete for food resources. Consequently, skinks have been introduced to Ile aux Aigrettes, another small Mauritian island that has been cleared of rats. However, the island has been invaded by Asian Musk Shrews (Suncus murinus), a commensal species spread by man well beyond its natural Asian range. Our aim was to use next-generation sequencing to analyse the diets of the shrews and skinks to look for niche competition. DNA was extracted from skink faeces and from the stomach contents of shrews. Application of shrew- and skink-specific primers revealed no mutual predation. The DNA was then amplified using general invertebrate primers with tags to identify individual predators, and then sequenced by 454 pyrosequencing. 119 prey MOTUs (molecular taxonomic units) were isolated, although none could be identified to species. Seeding of cladograms with known sequences allowed higher taxonomic assignments in some cases. Although most MOTUs were not shared by shrews and skinks, Pianka's niche overlap test showed significant prey overlap, suggesting potentially strong competition where food resources are limited. These results suggest that removal of the shrews from the island should remain a priority.

Imaging of a circumsolar dust ring near the orbit of Venus.

The gravitational interaction of dust in the zodiacal cloud with individual planets is expected to give rise to ringlike features: Such a circumsolar ring has been observed associated with Earth, but such resonance rings have not been confirmed to exist for other planets. Here, we report on sensitive photometric observations, based on imaging from the STEREO mission, that confirm the existence of a dust ring at the orbit of Venus. The maximum overdensity of dust in this ring, compared to the zodiacal cloud, is ~10%. The radial density profile of this ring differs from the model used to describe Earth's ring in that it has two distinct steplike components, with one step being interior and the other exterior to the orbit of Venus.

Measurement of direct photons in Au+Au collisions at √(s(NN))=200 GeV.

We report the measurement of direct photons at midrapidity in Au+Au collisions at √(s(NN))=200 GeV. The direct photon signal was extracted for the transverse momentum range of 4 GeV/c

First record of Neoxysomatium brevicaudatum through the non-invasive sampling of Anguis fragilis: complementary morphological and molecular detection.

Relatively few studies have examined the parasite fauna of British reptiles, partly due to the cryptic nature and low population density of these hosts. Here we examined 12 populations of the slow worm Anguis fragilis which, unlike other UK lizards, occurs at locally high population densities. Morphological examination of non-invasively collected faecal samples revealed the presence of Neoxysomatium brevicaudatum and a second unidentified nematode species. Although previously unrecorded from slow worms in the UK, N. brevicaudatum was present in 38% of animals (mean intensity 70.9, range 1-686). Morphological identification was confirmed by sequencing the 18S ribosomal gene. The use of the species-specific, cytochrome oxidase I mitochondrial gene primers proved an efficient alternative to conventional, microscope screening for parasites, although the original identification of N. brevicaudatum was dependent upon morphological characters. Sequencing also identified the second, smaller nematode as belonging to the Rhabdiasidae family: this species was even more common at a prevalence of 83% (mean intensity 102.8, range 1-2000). While increasing our knowledge of the UK macroparasite fauna, this work demonstrates the benefits of a combined morphological-molecular approach.

First Report of Cylindrocladiella parva as a Grapevine Pathogen in New Zealand.

Isolates morphologically identified as Cylindrocladiella parva were isolated from characteristic black foot symptoms on a grapevine (Vitis vinifera) rooted on 101-14 rootstock from Central Otago in 2005 and 101-14 rootstocks from a nursery in the Auckland Region in 2007 and 2008. On potato dextrose agar, the isolates initially produced cottony, white mycelia that turned grayish cream or golden cream within 10 days, the initially tawny colony undersides becoming dark brown with age. Conidia (0 to 1 septate; 16.4 to 17.0 [16.7] × 2.3 to 2.6 [2.5] µm) and abundant chlamydospores were produced. To confirm identity of the isolates, genomic DNA was extracted and the ribosomal DNA (rDNA) and ß-tubulin gene were amplified and sequenced (3,4). Sequences of the PCR products were compared with sequences in GenBank. The rDNA (535 bp) and ß-tubulin (297 bp) sequences of the four isolates were 100 and 99% identical, respectively, to reported sequences of C. parva in GenBank (AY793454, grapevine isolate (4)/AY793455 for rDNA; AY793486/AY793488, grapevine isolate (4)/AY793489/HM034822 for ß-tubulin). Although C. parva was previously isolated from grapevines in New Zealand (2) and rootstocks of mature grapevines, cuttings, and graft unions of grafted young grapevines in South Africa (4), its role as a pathogen of Vitis spp. has not been confirmed (2,4). However, it has been reported as a pathogen of Eucalyptus spp. (1) and was also isolated from Telopea speciosissima and Macadamia integrifolia in New Zealand (2,4). The C. parva isolates were tested as a mixed inoculum (four isolates) for pathogenicity on roots of 10 grapevine rootstock plants each of cvs. 101-14 and Schwarzmann (Sch). The rootstocks were grown in potting mix for 4 months, after which the root systems of all vines were wounded with an asparagus knife with a sharp, square tip, driven vertically down into the soil at four equidistant locations approximately 8 cm from the trunk. Each plant was inoculated with 50 ml of the mixed-isolate conidial suspension (106/ml), or 50 ml water (controls), followed by 50 ml of water. After 7 months of growth, the plants were harvested. For C. parva-inoculated plants, internal blackening of the stem base tissue was observed. Isolations from surface-sterilized trunk bases recovered C. parva from four and nine plants of 101-14 and Sch, respectively, with C. parva infections in 25 and 48%, respectively, of the four wood pieces taken per plant. Plants inoculated with water had no blackening and no C. parva was isolated from their stem bases. Mean shoot dry weights of inoculated plants (17.9 and 15.0 g for 101-14 and Sch, respectively) were significantly lower (P = 0.035) than noninoculated controls (26.5 and 20.0 g for 101-14 and Sch, respectively). Mean root dry weights were reduced by C. parva inoculation, although not significantly (32.7 and 27.0 g for C. parva inoculated 101-14 and Sch, respectively, and 36.2 and 27.4 g for control 101-14 and Sch, respectively). To our knowledge, this is the first report of C. parva as a pathogen of grapevines (2,4) and suggests that along with Cylindrocarpon spp., C. parva is part of the pathogen complex responsible for black foot of grapevines. References: (1) P. W. Crous et al. Plant Pathol. 42:302, 1993. (2) P. D. Gadgil et al. Fungi on Trees and Shrubs in New Zealand. Fungal Diversity Press, Hong Kong, 2005. (3) N. L. Glass and G. C. Donaldson. Appl. Environ. Microbiol. 61:1323, 1995. (4) G. J. van Coller et al. Australas. Plant Pathol. 34:489, 2005.

Enhanced production of direct photons in Au + Au collisions at square root(S(NN)) = 200 GeV and implications for the initial temperature.

The production of e+ e- pairs for m(e+ e-)<0.3 GeV/c2 and 1

Charged Kaon interferometric probes of space-time evolution in Au+Au collisions at sqrt[S(NN)]=200 GeV.

Bose-Einstein correlations of charged kaons are used to probe Au+Au collisions at sqrt[S(NN)]=200 GeV and are compared to charged pion probes, which have a larger hadronic scattering cross section. Three-dimensional Gaussian source radii are extracted, along with a one-dimensional kaon emission source function. The centrality dependences of the three Gaussian radii are well described by a single linear function of N(part)1/3 with a zero intercept. Imaging analysis shows a deviation from a Gaussian tail at r greater than or approximately equal to 10 fm, although the bulk emission at lower radius is well described by a Gaussian. The presence of a non-Gaussian tail in the kaon source reaffirms that the particle emission region in a heavy-ion collision is extended, and that similar measurements with pions are not solely due to the decay of long-lived resonances.

Suppression pattern of neutral pions at high transverse momentum in Au + Au collisions at sqrt[sNN]=200 GeV and constraints on medium transport coefficients.

For Au + Au collisions at 200 GeV, we measure neutral pion production with good statistics for transverse momentum, pT, up to 20 GeV/c. A fivefold suppression is found, which is essentially constant for 5 < pT < 20 GeV/c. Experimental uncertainties are small enough to constrain any model-dependent parametrization for the transport coefficient of the medium, e.g., q in the parton quenching model. The spectral shape is similar for all collision classes, and the suppression does not saturate in Au + Au collisions.

Particle-species dependent modification of jet-induced correlations in Au+Au collisions at sqrt[s_{NN}]=200 GeV.

Measurements in Au+Au collisions at sqrt[s_{NN}]=200 GeV of jet correlations for a trigger hadron at intermediate transverse momentum (p_{T,trig}) with associated mesons or baryons at lower p_{T,assoc} indicate strong modification of the away-side jet. The ratio of jet-associated baryons to mesons increases with centrality and p_{T,assoc}. For the most central collisions, the ratio is similar to that for inclusive measurements. This trend is incompatible with in-vacuum fragmentation but could be due to jetlike contributions from correlated soft partons, which recombine upon hadronization.

Source breakup dynamics in Au + Au collisions at sqrt[s(NN)]=200 GeV via three-dimensional two-pion source imaging.

A three-dimensional correlation function obtained from midrapidity, low p(T), pion pairs in central Au+Au collisions at sqrt[s(NN)]=200 GeV is studied. The extracted model-independent source function indicates a long range tail in the directions of the pion pair transverse momentum (out) and the beam (long). A proper breakup time tau(0) ~ 9 fm/c and a mean proper emission duration Delta tau ~ 2 fm/c, leading to sizable emission time differences ({|Delta t(LCM)|} approximately 12 fm/c), are required to allow models to be successfully matched to these tails. The model comparisons also suggest an outside-in "burning" of the emission source reminiscent of many hydrodynamical models.

Intra-specific variation in resting metabolic rate in MF1 mice is not associated with membrane lipid desaturation in the liver.

The 'membrane pacemaker' hypothesis provides a putative mechanistic linkage between variations in energy metabolism, rates of ageing and lifespan across different species. Within species we have found positive associations between longevity and metabolism, which contrast the inter-specific trends. It is of interest to know therefore how levels of lipid desaturation in membranes are linked to variation in metabolism between individuals within species. We explored this problem by extracting membrane fatty acids from the livers of mice that varied in their metabolic rate, in a strain (MF1) where we have previously demonstrated a positive association between metabolism and lifespan. We measured resting metabolic rate (RMR) in 60 mice, each measured on three occasions, and measured their body compositions using dual energy X-ray absorptiometry (DXA). We selected 28 individuals that exhibited a wide variation in their mean resting metabolic rates (RMR) and extracted membrane lipids from the livers of these mice post mortem and analysed them for the patterns of contribution of different fatty acids. We then sought associations between the levels of membrane desaturation and the individual variability in RMR, using the proportional contributions of each fatty acid as predictors in a stepwise regression or by re-describing the variation in fatty acyl lipids using a PCA analysis and then seeking associations between scores on the derived components and RMR. We used whole animal RMRs and also RMR with the effects of body composition (fat free mass) removed. The level of individual variation in RMR was consistent with our previous observations. There was a significant positive association (p=0.019) between the proportion of palmitic acid (16:0) in the membranes and RMR, which was strengthened (p=0.014) when we adjusted RMR for differences in fat free mass. The proportion of palmitic acid (16:0) explained 20.9% of the individual variation in residual RMR. There was no association between RMR or mass adjusted RMR and the proportional representation of any other fatty acid, including 22:6 (DHA) predicted by the membrane pacemaker hypothesis to be of particular significance. High levels of saturated fatty acids in the membranes of mice with high rates of metabolism may contribute to their greater longevity, but the mechanism tying together increased membrane saturation with elevated RMR remains unclear.

Elliptic flow for phi mesons and (anti)deuterons in Au+Au collisions at square root of sNN=200 GeV.

Differential elliptic flow (v(2)) for phi mesons and (anti)deuterons (d)d is measured for Au+Au collisions at square root of sNN=200 GeV. The v(2) for phi mesons follows the trend of lighter pi+/- and K+/- mesons, suggesting that ordinary hadrons interacting with standard hadronic cross sections are not the primary driver for elliptic flow development. The v(2) values for (d)d suggest that elliptic flow is additive for composite particles. This further validation of the universal scaling of v(2) per constituent quark for baryons and mesons suggests that partonic collectivity dominates the transverse expansion dynamics.

J/psi production versus centrality, transverse momentum, and rapidity in Au+Au collisions at square root sNN=200 GeV.

The PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) has measured J/psi production for rapidities -2.2

System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at square root sNN=200 and 62.4 GeV.

We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at square root sNN=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.

Evidence for a long-range component in the pion emission source in Au+Au collisions at sqrt sNN=200 GeV.

Emission source functions are extracted from correlation functions constructed from charged pions produced at midrapidity in Au+Au collisions at sqrt[s(NN)]=200 GeV. The source parameters extracted from these functions at low k(T) give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kinematic considerations. The possible role of a halo of secondary pions from resonance emissions is explored.

Scaling properties of azimuthal anisotropy in Au+Au and Cu+Cu Collisions at sqrt[s NN]=200 GeV.

Differential measurements of elliptic flow (v2) for Au+Au and Cu+Cu collisions at sqrt[sNN]=200 GeV are used to test and validate predictions from perfect fluid hydrodynamics for scaling of v2 with eccentricity, system size, and transverse kinetic energy (KE T). For KE T identical with mT-m up to approximately 1 GeV the scaling is compatible with hydrodynamic expansion of a thermalized fluid. For large values of KE T mesons and baryons scale separately. Quark number scaling reveals a universal scaling of v2 for both mesons and baryons over the full KE T range for Au+Au. For Au+Au and Cu+Cu the scaling is more pronounced in terms of KE T, rather than transverse momentum.

Measurement of direct photon production in p+p collisions at sqrt[s] = 200 GeV.

Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < pT < 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for pT >5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for pT >7 GeV/c.

Dense-medium modifications to jet-induced hadron pair distributions in Au+Au collisions at sqrt s NN=200 GeV.

Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at sqrt[s(NN)]=200 GeV. The distribution of jet-associated partner hadrons (1.0

Continuous peripheral nerve block in combat casualties receiving low-molecular weight heparin.

BACKGROUND: Continuous peripheral nerve block (CPNB) is an important therapeutic tool in the anaesthetic and analgesic management of combat casualties at Walter Reed Army Medical Center (WRAMC). We describe our experience using CPNB techniques in combat trauma patients treated with low-molecular weight heparin (LMWH). Guidelines used at our institution for managing CPNB catheters in patients being treated with LMWH are introduced. METHODS: From March 2003 to April 2005, 187 combat casualties treated by the WRAMC regional anaesthesia/acute pain section using CPNB were evaluated retrospectively by electronic chart review. Patient characteristic data, CPNB type, duration of CPNB, indication for LMWH [enoxaparin sodium injection (Lovenox-Sanofi Aventis, Bridgewater, NJ, USA)], enoxaparin dose (mg) before and after catheter insertion and removal, time from CPNB placement and removal to enoxaparin dose, and complications were recorded. RESULTS: Median enoxaparin dose and time given before catheter insertion were 30 mg and 21 h, respectively. Median enoxaparin dose was also 30 mg given a median of 12 h after peripheral nerve catheter placement. Catheters remained in situ for a median of 8 days (range 1-33 days). Catheter specific complications were infrequent and identified in 7 (3.7%) patients (two catheter malfunction-kinking, catheter tip dislodgement in situ, two superficial catheter site infections and two catheter dislocations). There were no catheter-related bleeding complications evident in this study. CONCLUSIONS: Information regarding the safety of CPNB in patients treated with LMWH for perioperative venous thromboembolism prevention is scarce. Our initial experience with CPNB and concurrent LMWH has not been complicated by catheter-related bleeding.