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OBJECTIVES: Patients with pectus excavatum (PE) after prior sternotomy for cardiac surgery present unique challenges for repair of PE. Open repairs have been recommended because of concerns about sternal adhesions and cardiac injury. We report a multi-institutional experience with repair utilizing substernal Nuss bars in this patient population. METHODS: Surgeons from the Chest Wall International Group were queried for experience and retrospective data on PE repair using substernal Nuss bars in patients with a history of median sternotomy for cardiac surgery (November 2000 to August 2015). A descriptive analysis was performed. RESULTS: Data for 75 patients were available from 14 centres. The median age at PE repair was 9.5 years (interquartile range 10.9), and the median Haller index was 3.9 (interquartile range 1.43); 56% of the patients were men. The median time to PE repair was 6.4 years (interquartile range 7.886) after prior cardiac surgery. Twelve patients (16%) required resternotomy before support bar placement: 7 preemptively and 5 emergently. Sternal elevation before bar placement was used in 34 patients (45%) and thoracoscopy in 67 patients (89%). Standby with cardiopulmonary bypass was available at 9 centres (64%). Inadvertent cardiac injury occurred in 5 cases (7%) without mortality. CONCLUSIONS: Over a broad range of institutions, substernal Nuss bars were used in PE repair for patients with a history of sternotomy for cardiac surgery. Several technique modifications were reported and may have facilitated repair. Cardiac injury occurred in 7% of cases, and appropriate resources should be available in the event of complications. Prophylactic resternotomy was reported at a minority of centres. [ABSTRACT FROM AUTHOR]

A transgenic line of Yorkshire (YK) pigs named the Cassie (CA) line was produced with a low copy number phytase transgene inserted in the genome. The transgenic line efficiently digests P, Ca, and other major minerals of plant dietary origin. The objectives of this study were to 1) compare carcass and tissue nutrient composition and meat quality traits for third generation hemizygous CA line market BW finisher pigs (n = 24) with age-matched conventional YK finisher pigs (n = 24) and 2) examine effects of outbreeding with high-index conventional YK boars on modifying carcass leanness from the third to sixth generations in CA line finisher boars (n = 73) and gilts (n = 103). Cassie boars (n = 12) and CA gilts (n = 12) were fed diets without supplemental P and comparable numbers of age-matched YK boars and gilts fed diets containing supplement P were raised throughout the finisher phase. The pigs were slaughtered and then fabricated into commercial pork primais before meat composition and quality evaluation. Proximate and major micronutrient composition was determined on tissues including fat, kidney, lean, liver, and skin. The main difference observed was greater (P = 0.033) crude fat content in CA boar carcasses and increased (P < 0.04) leaf lard in both CA boars and gilts but no differences were observed (P = 0.895 and P = 0.223, respectively) in carcass backfat thickness as compared with YK pigs. There were no substantive differences in tissue composition, except for CA boar kidneys. Numerous changes in the mineral, fatty acid, and indispensable AA composition for CA boar kidneys were not apparent in CA gilts. These changes may point to adaptive physiological changes in the boar kidney necessary for homeostatic regulation of mineral retention related to phytase action rather than to insertion of the transgene. However, from a meat composition perspective, transgenic expression of phytase in the CA line of YK pigs had little overall effect on meat composition. Outbreeding of high-index CA gilts with high-index commercial YK boars linearly reduced (P = 0.002) back fat thickness with a corresponding linear increase (P = 0.001) in lean yield in finisher CA gilts, although no change in these parameters was observed in CA finisher boars. The increase in lean yield in CA gilts by selective breeding without affecting the level of salivary phytase activity documents the value of conventional genetic selection in conjunction with genetic modification. [ABSTRACT FROM AUTHOR]

A transgenic Cassie (CA) line of Yorkshire (YK) pigs was developed using a transgene composed of the mouse parotid secretory protein promoter linked to the Escherichia coli phytase gene integrated in chromosome 4. Previous studies documented that salivary secretion of phytase was sufficient to enable efficient digestion of plant feed phytate P. In the present study the catalytic properties and tissue distribution of the phytase in CA pigs were determined by a combination of enzymatic assays, immunohistochemistry, and immunoblots of tissue samples. The E. coli phytase had a mass of 44.82 kDa whereas the phytase secreted in CA saliva had a mass of 52.42 kDa as a result of glycosylation of the enzyme in the parotid gland. Despite the difference in size, the 2 enzymes exhibited similar substrate specificities, and substrate affinity (Km) and maximum hydrolytic activity (Vmax) catalytic properties. Phytase assays showed that the enzyme was present at high specific activity in the salivary glands with low activity in the soft palate and essentially none in the kidney, lean (muscle), liver, or skin of CA pigs and none in YK pigs. This conclusion was supported by immunoblot analysis using a polyclonal anti-phytase antibody. Immunohistochemical analysis of 83 different tissue locations of CA and YK pigs confirmed the ubiquitous presence of phytase in serous cells of the salivary glands and the localized presence of phytase in both serous and mixed cell types in the submucosal glands of the oropharynx; in the pharynx, tonsils, and esophagus; in some Bowman's glands in the nasal mucosa and eustachian tube; and in the prostate gland of CA boars. Furthermore, it showed the absence of phytase from the kidney, lean, liver, and skin of CA pigs. Phytase was not detected in any of the conventional YK tissues tested. The phytase was found to be glycosylated with the allergenic galactose-α-1,3-galactose (a-gal) epitope by immunoblotting using α-gal specific monoclonal antibodies. Galactose-α-1,3-galactose glycosylation of proteins is a common feature of pork and other red meats. The α-gal epitope was shown to be associated with a few proteins in muscle and skin but with the greatest number of proteins in kidney and parotid tissues of CA and YK pigs. The absence of phytase from the major food tissues and the displacement of other α-gal glycosylated proteins in the parotid glands by α-gal glycosylated phytase in conjunction with previously published data support the contention that expression of the novel phytase has minimal influence on pork quality and safety. [ABSTRACT FROM AUTHOR]

Understanding the spectral properties of boundary integral operators in acoustic scattering has important practical implications, such as for the analysis of the stability of boundary element discretizations or the convergence of iterative solvers as the wave number k grows. Yet, little is known about spectral decompositions of the standard boundary integral operators in acoustic scattering. Theoretical results are mainly available on the unit circle, where these operators diagonalize in a simple Fourier basis. In this paper we investigate spectral decompositions for more general smooth domains. Based on the decomposition of the acoustic Green's function in elliptic coordinates, we give spectral decompositions on ellipses. For general smooth domains we show that approximate spectral decompositions can be given in terms of circle Fourier modes transplanted onto the boundary of the domain. An important underlying question is whether the operators are normal. Based on previous numerical investigations it appears that the standard boundary integral operators are normal only when the domain is a ball and here we prove that this is indeed the case for the acoustic single layer potential. We show that the acoustic single, double and conjugate double layer potential are normal in a scaled inner product on the ellipse. On more general smooth domains the operators can be split into a normal component plus a smooth perturbation. Numerical computations of pseudospectra are presented to demonstrate the nonnormal behaviour on general domains. [ABSTRACT FROM AUTHOR]

Aims A next-generation, Illumina-based sequencing approach was used to characterize the bacterial community at ten sites along the Upper Mississippi River to evaluate shifts in the community potentially resulting from upstream inputs and land use changes. Furthermore, methodological parameters including filter size, sample volume and sample reproducibility were evaluated to determine the best sampling practices for community characterization. Methods and Results Community structure and diversity in the river was determined using Illumina next-generation sequencing technology and the V6 hypervariable region of 16S r DNA. A total of 16 400 operational taxonomic units ( OTUs) were observed (4594 ± 824 OTUs per sample). Proteobacteria, Actinobacteria, Bacteroidetes, Cyanobacteria and Verrucomicrobia accounted for 93·6 ± 1·3% of all sequence reads, and 90·5 ± 2·5% belonged to OTUs shared among all sites ( n = 552). Among nonshared sequence reads at each site, 33-49% were associated with potentially anthropogenic impacts upstream of the second sampling site. Alpha diversity decreased with distance from the pristine headwaters, while rainfall and pH were positively correlated with diversity. Replication and smaller filter pore sizes minimally influenced the characterization of community structure. Conclusions Shifts in community structure are related to changes in the relative abundance, rather than presence/absence of OTUs, suggesting a 'core bacterial community' is present throughout the Upper Mississippi River. Significance and Impact of the Study This study is among the first to characterize a large riverine bacterial community using a next-generation-sequencing approach and demonstrates that upstream influences and potentially anthropogenic impacts can influence the presence and relative abundance of OTUs downstream resulting in significant variation in community structure. [ABSTRACT FROM AUTHOR]

A line of transgenic Yorkshire pigs referred to as the Cassie (CA) line was generated, which possessed a stable, low copy number phytase transgene insertion that enabled phytase secretion in the saliva. This study was conducted to assess growth and efficacy for improving P, Ca, and other macromineral utilization in the CA pigs receiving diets typical of those used for commercial swine production. In Exp. 1, 12 CA boars and 12 CA gilts fed diets without supplemental P gained weight and exhibited feed efficiency similar to conven-tional age-matched 12 Yorkshire boars and 12 Yorkshire gilts raised on similar diets with supplemental P. Serum concentrations of P and Ca were similar for CA and Yorkshire pigs during the growing and finishing phases, indicating that the CA pigs were not P limited. In Exp. 2, 6 CA (13.1 kg BW) and 6 Yorkshire barrows (8.8 kg BW) were fed 3 diets (control; low in Ca and P; and low in Ca, P, and CP) over 3 phases. The CA barrows fed the diet without supplemental P retained 25 to 40% (P < 0.001), 77 to 91% (P < 0.001), and 27 to 56% (P < 0.001) more P during the weaning, growing, and finishing phases, respectively, than conventional Yorkshire barrows fed similar diets without supplemental P. In Exp. 3, CA and Yorkshire barrows of similar ages weighing 66.2 ± 1.7 kg (« = 10) and 50.0 ± 1.0 kg (n = 10), respectively, were used. The P retention of CA finisher barrows fed a diet without supplemental P was 34% greater (P < 0.001) than conventional Yorkshire barrows fed the same diet with 750 units of exogenous phytase/kg diet. Urinary Ca to P ratio in the CA pigs was 0.27, whereas that for the Yorkshire barrows was 30, thereby, indicating that the Yorkshire barrows suffered a P deficiency. Furthermore, digestive utilization of major electrolyte macrominer-als, K and Na, was improved {P < 0.05) by 18 and 16%, respectively, in the CA finisher pigs compared with the conventional Yorkshire finisher pigs fed phytase; how-ever, only K exhibited enhanced retention. In conclusion, the CA line pigs secrete sufficient phytase from the sali-vary glands to enable efficient digestion of plant P, Ca, and major electrolyte macrominerals. [ABSTRACT FROM AUTHOR]

ABSTRACT We investigate the structure of the planetary nebula NGC 2371 using [O iii] λ5007 imaging taken with the Jacobus Kapteyn 1.0 m telescope, and [N ii] λ6584, [O iii] λ5007 and Hα results acquired with the Hubble Space Telescope. These are supplemented with archival mid-infrared (MIR) observations taken with the Spitzer Space Telescope. We note the presence of off-axis low-ionization spokes along a position angle of 65°, and associated collars of enhanced [O iii] emission. The spokes appear to consist of dense condensations having low-excitation tails, possibly arising due to ultraviolet shadowing and/or ram-pressure stripping of material. Line ratios imply that most of the emission arises through photoionization, and is unlikely to derive from post-shock cooling regions. An analysis of these features in the MIR suggests that they may also be associated with high levels of emission from polycyclic aromatic hydrocarbons (PAHs), together with various permitted and forbidden line transitions. Such high levels of PAH emission, where they are confirmed, may develop as a result of preferentially enhanced far-ultraviolet pumping of the molecules, or shattering of larger grains within local shocks. Although H2 emission may also contribute to these trends, it is argued that shock-excited transitions would lead to markedly differing results. We finally note that thin filaments and ridges of [O iii] emission may indicate the presence of shock activity at the limits of the interior envelope, as well as at various positions within the shell itself. We also note that radially increasing fluxes at 3.6, 5.8 and 8.0 μm, relative to the emission at 4.5 μm, may arise due to enhanced PAH emission in external photodissociative regions. [ABSTRACT FROM AUTHOR]

ABSTRACT NGC 6369 is a double-shell planetary nebula consisting of a bright annular inner shell with faint bipolar extensions and a filamentary envelope. We have used ground- and space-based narrow-band optical and near-infrared (near-IR) images, broad-band mid-IR images, optical long-slit echelle spectra and mid-IR spectra to investigate its physical structure. These observations indicate that the inner shell of NGC 6369 can be described as a barrel-like structure shape with polar bubble-like protrusions, and reveal evidence for H2 and strong polycyclic aromatic hydrocarbons emission from a photodissociative region (PDR) with molecular inclusions located outside the bright inner shell. High-resolution Hubble Space Telescope narrow-band images reveal an intricate excitation structure of the inner shell and a system of 'cometary' knots. The knotty appearance of the envelope, the lack of kinematical evidence for shell expansion and the apparent presence of emission from ionized material outside the PDR make us suggest that the envelope of NGC 6369 is not a real shell, but a flattened structure at its equatorial regions. We report the discovery of irregular knots and blobs of diffuse emission in low-excitation and molecular line emission that are located up to 80 arcsec from the central star, well outside the main nebular shells. We also show that the filaments associated to the polar protrusions have spatial extents consistent with post-shock cooling regimes, and likely represent regions of interaction of these structures with surrounding material. [ABSTRACT FROM AUTHOR]

Summary Background Hepatoerythropoietic porphyria (HEP) is a rare form of porphyria that results from a deficiency of uroporphyrinogen decarboxylase (UROD). The disease is caused by homoallelism or heteroallelism for mutations in the UROD gene. Objective To study a 19-year-old woman from Equatorial Guinea, one of the few cases of HEP of African descent and to characterize a new mutation causing HEP. Methods Excretion of porphyrins and residual UROD activity in erythrocytes were measured and compared with those of other patients with HEP. The UROD gene of the proband was sequenced and a new mutation identified. The recombinant UROD protein was purified and assayed for enzymatic activity. The change of amino acid mapped to the UROD protein and the functional consequences were predicted. Results The patient presented a novel homozygous G170D missense mutation. Porphyrin excretion showed an atypical pattern in stool with a high pentaporphyrin III to isocoproporphyrin ratio. Erythrocyte UROD activity was 42% of normal and higher than the activity found in patients with HEP with a G281E mutation. The recombinant UROD protein showed a relative activity of 17% and 60% of wild-type to uroporphyrinogen I and III respectively. Molecular modelling showed that glycine 170 is located on the dimer interface of UROD, in a loop containing residues 167-172 that are critical for optimal enzymatic activity and that the carboxyl side chain from aspartic acid is predicted to cause negative interactions between the protein and the substrate. Conclusions The results emphasize the complex relationship between the genetic defects and the biochemical phenotype in homozygous porphyria. [ABSTRACT FROM AUTHOR]

BSTRACT [ABSTRACT FROM AUTHOR]

We present the imaging and spectroscopy of NGC 40 acquired using the Spitzer Space Telescope and the Infrared Space Observatory. These are used to investigate the nature of emission from the central nebular shell, from the nebular halo and from the associated circumnebular rings. It is pointed out that a variety of mechanisms may contribute to the mid-infrared (MIR) fluxes, and there is evidence for a cool dust continuum, strong ionic transitions and appreciable emission by polycyclic aromatic hydrocarbons (PAHs). Prior observations at shorter wavelengths also indicate the presence of warmer grains and the possible contribution of H transitions. Two of these components (warm dust with K and PAH emission bands) appear capable, in combination, of explaining the infrared colours of the rings and halo, although the flux ratios are also consistent with shock-excited H v= 0-0 emission. It is noted that whilst the surface brightness of the rings is greater in the longer wave (5.8- and m) photometric channels, their fractional fluxes (when compared to the halo) are greater at 3.6 and m, a trend which is similar to those observed in other planetary nebulae. It is also apparent that the relative intensities of the rings are greater than is observed for the Hα+[N ] transitions. It is suggested that an apparent jet-like structure to the north-east of the halo represents one of the many emission spokes that permeate the shell and which are observed for the first time in these MIR results. The spokes are likely to be caused by the percolation of UV photons through a clumpy interior shell, whilst the jet-like feature is enhanced due to locally elevated electron densities, a result of interaction between NGC 40 and the interstellar medium. It is finally noted that the presence of the PAH, 21- and 30-μm spectral features testifies to appreciable C/O ratios within the main nebular shell. Such a result is consistent with abundance determinations using collisionally excited lines, but not with those determined using optical recombination lines. [ABSTRACT FROM AUTHOR]

We have obtained 24 μm imaging, profiles and fluxes for 224 planetary nebulae (PNe) lying within the limits of the Galactic survey undertaken with the Multiband Imaging Photometer for Spitzer (MIPSGAL). It is noted that most of the PNe having extended 24 μm emission also possess circular morphologies, suggesting that the emission derives from cool grains located within the Asymptotic Giant Branch (AGB) mass-loss regimes. Certain of these haloes are found to have a surface brightness fall-off which may be consistent with secularly invariant mass loss within the PNe progenitors. By contrast, the m envelopes are detected out to smaller distances from the nuclei, and have a steeper rate of surface brightness fall-off; a phenomenon which may arise from changes in the excitation of polycyclic aromatic hydrocarbons (PAHs) within external photo-dissociation regimes (PDRs). Our 24 μm fluxes are compared to those in previously published studies, and this appears to indicate that many of the prior fluxes have been underestimated; a disparity may imply that previous aperture sizes were too small. We have also combined our 24 μm fluxes with measures at shorter mid-infrared (MIR) wavelengths, taken with the Infrared Array Camera (IRAC). These are used to investigate the positioning of PNe within the IRAC-MIPSGAL colour planes. The [8.0]-[24] and [5.8]-[24] colours are found to be large, and extend over the respective ranges 3.4-8.7 mag, and 5.4-10.3 mag; indices which are only explainable where a broad range of mechanisms contribute to the fluxes, including PAH bands, cool dust continua and a variety of ionic transitions. These and other components also affect the morphologies of the sources, and lead to wavelength-dependent changes in the widths of the profiles. [ABSTRACT FROM AUTHOR]

NGC 7009 is a fascinating example of a high-excitation, elliptical planetary nebula (PN) containing circumnebular rings, and FLIERs and jets along the major axis. We present visual spectroscopy along multiple position angles through the nucleus, taken with the Observatorio Astronomico Nacional (Mexico); mid-infrared (MIR) spectroscopy and imaging acquired using the Infrared Space Observatory ( ISO) and Spitzer Space Telescope ( SST), and narrow-band imaging obtained using the Hubble Space Telescope ( HST). The data show that the mid-infrared (MIR) continuum is dominated by a broad ≈100 K continuum, and a strong excess attributable to crystalline silicate emission. The primary peaks in this excess are similar to those observed in Forsterite and clino- and ortho-enstatite. The MIR images, by contrast, appear to be dominated by ionic transitions, with the m transition of [Ar ] being important in the m band. The morphology and size of the envelope are found to vary with wavelength, with the largest dimensions occurring at m - a trend which is also reflected in an increase in the m and m ratios with distance from the nucleus. The visual spectroscopy permits us to map density and temperature throughout the shell, and confirm that the lowest values of are located close to the ansae, where densities appear to be of the order of 900-2600 cm. We provide mean line intensities for 116 transitions in six regions of the shell, and use mapping to confirm a systematic increase in excitation in the outer portions of the envelope. We finally use the ground-based spectroscopy, and ratioing of HST images to investigate the presence of shocks in the ansae and interior envelope. It is concluded that line ratios in the ansae may be partially consistent with shock excitation, although these features are primarily dominated by photoionization. We also note evidence for shock excitation at the limits of the interior elliptical shell, and for multiple bow-shock structures centred upon the ansae. The orientations of the easterly bow-shocks may have varied over time, indicating precession of the collimating engine at a rate of deg yr, whilst the outward splaying of the westerly 'jet' appears consistent with shock refraction modelling. We finally note that HST observations of the halo rings show them to have widths of the order of ∼1-3 arcsec, and steep changes in surface brightness consistent with local shock activity. [ABSTRACT FROM AUTHOR]

The supernova remnant (SNR) G357.7+0.3 appears to have caused considerable shredding of the local interstellar medium (ISM), leading to the formation of multiple cloud fragments having bright rims and cometary structures. We investigate five of these regions using mid-infrared (MIR) imaging and photometry deriving from the Spitzer Space Telescope ( SST), as well as photometry deriving from the 2MASS near-infrared all sky survey, the Mid-Course Science Experiment (MSX) and the Multiband Imaging Photometer for Spitzer (MIPSGAL) survey of the Galactic plane. It is noted that two of the rims show evidence for emission by shock-excited H transitions, whilst the centres of the clouds also show evidence for dark extinction cores, observed in silhouette against the bright emission rims. Levels of extinction for these cores are determined to be of the order of mag, whilst densities n(H ) are of the order of ∼10 cm, and masses in the region of ∼40-100 M. It is shown that the wavelength dependence of extinction is probably similar to that of Cardelli et al. and Martin & Whittet, but differs from the MIR extinction trends of Indebetouw et al. The distributions of Class I young stellar objects (YSOs) imply that many of them are physically associated with the clouds, and were likely formed as a result of interaction between the clouds and SN winds. A determination of the spectral energy distributions (SEDs) of these stars, together with 2D radiative transfer modelling of their continua is used to place constraints upon their properties. [ABSTRACT FROM AUTHOR]

We provide mid-infrared (MIR) imaging, photometry and profiles for the Galactic supernova remnants (SNRs) 00.1, 02.5, 00.0 and W28 based upon data deriving for the Galactic Legacy Infrared Mid-Plane Survey Extraordinaire (GLIMPSE). All of the sources show evidence for interaction with the interstellar medium (ISM), leading to curved frontal structures and apparent voids in the ISM. An analysis of the spectral energy distributions (SEDs) of Class I young stellar objects (YSOs) within the north-westerly interaction region of W28, and of the density of stars within the borders of the SNR, suggests that many of them may have been triggered by the SN event. 2D radiative transfer modelling permits us to constrain the physical parameters of the sources. It is also noted that the location of Class I YSOs about the perimeter of 00.1, and close to frontal arcs associated with SNR 02.5, suggests that star formation may have been triggered by these SNRs as well. Finally, it is found that the MIR colours of the frontal structures appear consistent with shock excitation of the transitions of H2, although it is conceivable that emission by polycyclic aromatic hydrocarbons (PAHs) may also play a role. Where the latter mechanism is relevant, it is possible that emission derives from the shattering of larger grains in frontal regions, leading to increased volume densities of PAH carrying grains. [ABSTRACT FROM AUTHOR]

We have investigated the mid-infrared (MIR) and visual structures of seven bipolar planetary nebulae (BPNe), using imaging and spectroscopy acquired using the Spitzer Space Telescope (SST), and the Observatorio Astronomico Nacional in Mexico. The results show that the sources are more extended towards longer MIR wavelengths, as well as having higher levels of surface brightness in the 5.8- and m bands. It is also noted that the m and m flux ratios increase with increasing distance from the nuclei of the sources. All of these latter trends may be attributable to emission by polycyclic aromatic hydrocarbons (PAHs) and/or warm dust continua within circumnebular photodissociation regions (PDRs). A corresponding decrease in the flux ratios m may, by contrast, arise due to changes in the properties of the PAH emitting grains. We note evidence for m ring-like structures in the envelope of NGC 2346, located in a region beyond the minor axis limits of the ionized envelope. An analysis of the inner two rings shows that whilst they have higher surface brightnesses at longer MIR wavelengths, they are relatively stronger (compared to underlying emission) at 3.6 and m. There is also evidence for point-reflection symmetry along the major axis of the outflow. Finally, the fall-off in surface brightness along the nebular minor axis suggests that progenitor mass-loss rates were more-or-less constant. NGC 6905 shows evidence for a centrally located and unresolved MIR emission excess. We show that whilst flux ratios are inconsistent with stellar and ionized gas components of emission, the emission can be explained in terms of shock-excited H2, or grain continuum and PAH emission bands. We provide the deepest image so far published of the outer visual structure of NGC 6445, and compare these results with Spitzer imaging at m. The distributions are quite distinct, and may indicate collimation of the outer ionized emission by a cylindrical PDR. We finally note that the MIR colours of the lobes and nuclei of the sources are radically different. It is also shown that m emission in BPNe differs from that for the generality of planetary nebulae. We discuss various mechanisms which may contribute to these differences of colour. [ABSTRACT FROM AUTHOR]

We present an analysis of the structure and properties of the compact H ii region Sh 2-89, and certain of the young stellar objects (YSOs) within this regime, using mid-infrared (MIR) mapping derived from the Spitzer Space Telescope ( SST) and visual slit spectroscopy of the inner regions of the source. We show that the region has a bipolar structure, and contains a variety of Class I and II YSOs. Much of the MIR emission appears to be dominated by polycyclic aromatic hydrocarbon emission bands, which cause strong increases in flux in the 5.8 and m photometric channels, whilst the variation of Hα, [N ii]λ6583 Å, [S ii] 6716+6731 Å and MIR emission profiles confirms the presence of complex ionization fronts, and ionization stratification. One of the sources in this region has been previously identified as a likely symbiotic star. We show however that whilst it contains TiO absorption bands, it shows little evidence for higher excitation He iiλ4686 Å or [O iii]λ5007 Å emission. Such a result does not rule out the possibility of the source being a symbiotic star, although we note that the detection limits on these lines, and the observed visual/infrared continuum, would make it difficult to fit it into either the D- or S-type symbiotic classifications. An analysis and modelling of the infrared continuum, on the other hand, together with a consideration of the associated H ii region, suggests that it is more likely to represent a Class II YSO in which most of the emission derives from a massive accretion disc. Where this is the case, then the star is likely to have a temperature K, mass M , luminosity L , and age in the range yr. It also appears to be associated with strong Hα emission which, where it derives from radiatively driven stellar/disc winds, and collimated or spherically symmetric mass outflows, would likely imply mass-loss rates of the order of to M (depending upon the outflow velocity ). Such a mass-loss rate is entirely plausible for this category of source, although it is also noted that the Hα may derive from other mechanisms as well, including chromospheric activity, and the ionization of circumstellar material – the result of interaction between local UV radiation fields and winds and the stellar accretion disc or envelope. [ABSTRACT FROM AUTHOR]

We report the results of visual spectroscopy, mid-infrared (MIR) mapping and photometry, and near-infrared photometry of two candidate symbiotic stars (IPHAS J193108.67+164950.5 and IPHAS J193709.65+202655.7) associated with extended MIR emission. Our analysis of the continua of these sources shows that they are likely to represent Class I–II young stellar objects (YSOs) in which most of the IR emission arises from circumstellar discs, and for which the physical characteristics (stellar temperatures, radii, masses and luminosities) are similar. The extended emission is characterized by a substantial increase in fluxes and dimensions to longer MIR wavelengths. This is likely to arise as a result of emission by polycyclic aromatic hydrocarbons within extended photodissociation regimes, centred upon more compact ionized regions responsible for much of the shorter wave emission. Such dual emission structures are characteristic of those observed in many compact H ii regions. Finally, we note that the clouds have asymmetrical structures and wind-swept morphologies, conceivably indicative of shock interaction with external winds. Where this is the case, then it is possible that the YSOs are located in regions of triggered star formation. [ABSTRACT FROM AUTHOR]

The motion of planetary nebulae through the interstellar medium (ISM) is thought to lead to a variety of observational consequences, including the formation of bright rims, deformation and fragmentation of the shells, and a shift of the central stars away from the geometric centres of the envelopes. These and other characteristics have been noted through imaging in the visual wavelength regime. We report further observations of such shells taken in the mid-infrared (MIR), acquired through programmes of Infrared Array Camera imaging undertaken using the Spitzer Space Telescope. NGC 2440 and NGC 6629 are shown to possess likely interacting haloes, together with ram-pressure-stripped material to one side of their shells. Similarly, the outer haloes of NGC 3242 and NGC 6772 appear to have been fragmented through Rayleigh–Taylor (RT) instabilities, leading to a possible flow of ISM material towards the inner portions of their envelopes. If this interpretation is correct, then it would suggest that NGC 3242 is moving towards the NE, a suggestion which is also supported through the presence of a 60 μm tail extending in the opposite direction, and curved bands of H emission in the direction of motion – components which may arise through RT instabilities in the magnetized ISM. NGC 2438 possesses strong scalloping at the outer limits of its asymptotic giant branch (AGB) halo, probably reflecting RT instabilities at the nebular/ISM interface We also note that the interior structure of the source has been interpreted in terms of a recombining shell, a hypothesis which may not be consistent with the central star luminosities. Finally, we point out that two of the rims (and likely shock interfaces) appear to have a distinct signature in the MIR, whereby relative levels of 8.0 μm emission are reduced. This may imply that the grain emission agents are depleted in the post-shock AGB regimes. [ABSTRACT FROM AUTHOR]

We present images of the planetary nebulae NGC 7354 and NGC 3242 in four mid-infrared (MIR) photometric bands centred at 3.6, 4.5, 5.8 and , the results of observations undertaken using the Spitzer Space Telescope. The resulting images show the presence of a halo and rings in NGC 3242, as previously observed through narrow-band imaging at visual wavelengths, as well as evidence for a comparable halo and ring system in NGC 7354. This is the first time that a halo and rings have been observed in the latter source. Similarly, whilst partial rings may have been previously detected in the MIR (for the source NGC 3132), the present observations appear to constitute the first detections of complete ring systems outside of the visual wavelength regime. The halo/core emission ratios appear to be preferentially higher at MIR wavelengths than is the case in the visible, and show less steep fall-offs than those observed in the [O iii] + 5007 Å transitions. The variation in surface brightness S with radial distance R, where this is approximated by the power-law relation , implies exponents in the inner portions of the haloes, and towards the outer limits of these structures. The value of β is also, in most cases, somewhat smaller at longer wavelengths. It is additionally noted that the , and flux ratios increase markedly away from the nuclei, and reach their maximum values in the haloes, where much of the longer wave flux may derive from dust band and continuum emission. An analysis of the rings suggests that some of them, at least, are likely to be associated with higher densities of dust particles, and that the gaseous and particle ring systems are likely to be spatially in register. Finally, we have analysed the formation of haloes as a result of radiatively accelerated mass loss in the AGB progenitors. Although the models assume that dust formation occurs in C-rich environments, we note that qualitatively similar results would be expected for O-rich progenitors as well. The model fall-offs in halo density are found to result in gradients in halo surface brightness which are similar to those observed in the visible and MIR. [ABSTRACT FROM AUTHOR]

We present evidence for interaction between the supernova remnant (SNR) G357.7+0.3 and nearby molecular clouds, leading to the formation of wind-swept structures and bright emission rims. These features are not observed at visual wavelengths, but are clearly visible in mid-infrared mapping undertaken using the Spitzer Space Telescope. Analysis of one of these clouds, the bright cometary structure G357.46+0.60, suggests that it contains strong polycyclic aromatic hydrocarbon emission features in the 5.8 and 8.0 μm photometric bands, and that these are highly variable over relatively small spatial scales. The source is also associated with strong variations in electron density; a far-infrared continuum peak associated with dust temperatures of ∼30 K; and has previously been observed in the 1720 MHz maser transition of OH, known to be associated with SNR shock excitation of interstellar clouds. This source also appears to contain a young stellar object (YSO) within the bright rim structure, with a steeply rising spectrum between 1.25 and 24 μm. If the formation of this star has been triggered recently by the SNR, then YSO modelling suggests a stellar mass , and luminosity . Finally, it is noted that a further, conical emission region appears to be associated with the Mira V1139 Sco, and it is suggested that this may represent the case of a Mira outflow interacting with a SNR. If this is the case, however, then the distance to the SNR must be ∼half of that determined from CS and 3–2 line radial velocities. [ABSTRACT FROM AUTHOR]

We present mid-infrared (MIR) photometry for 367 Galactic disc, bulge and Large Magellanic Cloud (LMC) planetary nebulae (PNe), determined using data acquired with the Spitzer Space Telescope, and through the Legacy Programs GLIMPSE II (Galactic Legacy Infrared Mid-plane Survey Extraordinaire II) and SAGE (Surveying the Agents of the Galaxy's Evolution). This has permitted us to make a comparison between the luminosity functions of bulge and LMC PNe, and between the MIR colours of all three categories of source. It is determined that whilst the luminosity functions of the LMC and bulge sources are likely to be closely similar, the [3.6]–[5.8] and [5.8]–[8-0] indices of LMC nebulae are different from those of their disc and bulge counterparts. This may arise because of enhanced polycyclic aromatic hydrocarbon emission within the LMC sources, and/or as a result of further, and more radical differences between the spectra of LMC and Galactic PNe. We also determine that the more evolved disc sources listed in the Macquarie/AAO/Strasbourg (MASH) catalogues of Parker et al. and Miszalski et al. have similar colours to those of the less evolved (and higher surface brightness) sources in the catalogue of Acker et al., a result which appears at variance with previous studies of these sources. [ABSTRACT FROM AUTHOR]

We have analysed the near-infrared (NIR) and far-infrared (FIR) colours of MASH I and MASH II (the Macquarie/AAO/Strasbourg surveys) planetary nebulae (PNe), using data deriving from the Two-Micron All-Sky Survey and Infrared Astronomical Satellite. We were able to identify ∼5 per cent of the sources in the NIR, and a slightly larger fraction (∼12 per cent) in the FIR. It is concluded that whilst the NIR colours of these nebulae are consistent with those of less evolved (and higher surface brightness) PNe, their FIR colours are markedly different. This disparity is likely to arise as a result of an evolution in dust temperatures, in their line emission characteristics, and in the relative contributions of the 8.6 and 11.3 μm polycyclic aromatic hydrocarbon emission features. A rump of ∼9 per cent of the detected sources have values which are lower than can be explained in terms of normal nebular evolution, however. If these are comparable in nature to the undetected PNe, then this would argue that ∼1 in 10 of MASH I and II nebulae may represent galactic H ii regions, Stromgren spheres, symbiotic nebulae or other unrelated categories of source. [ABSTRACT FROM AUTHOR]

Bipolar outflows appear to represent the ubiquitous products of post- and pre-main-sequence stellar evolution. However, although the outflows around young stellar objects (YSOs) have been observed over a broad range of wavelengths, from the ultraviolet through to the radio, there has been very little mapping of these sources at mid-infrared (MIR) wavelengths. The recent advent of the Spitzer Space Telescope ( SST) now permits us to correct this deficiency, and we present maps, profiles and images of seven bipolar sources, six of which appear to be new to the literature. It is found that although the bipolars have differing morphologies, reflecting the differing phases of their evolution, they nevertheless have many properties in common. These include the evidence for central tori of neutral material, in some cases associated with appreciable levels of extinction. We also note evidence for exterior photodissociation regimes (PDRs) about the ionized flows, responsible for strong polycyclic aromatic hydrocarbon (PAH) band emission in the 5.8 and bands. Such PDRs are also likely to be responsible for appreciable variations in flux ratios with position within the sources. Finally, it is noted that a large fraction of the sources are associated with stars in the earliest phases of their evolution – Class 0 and I stars in which infalling material is important, and dominates their spectral energy distributions in the MIR. One of the sources (G035.2−00.7) has previously been observed at visual, near-infrared (NIR) and millimetric wavelengths, whence it has been proposed that the spatio-kinematic properties of the source are best explained in terms of multiple nuclear outflows, and/or precession of an ionized jet. Our present results suggest that the characteristics of this source are much simpler than has previously been inferred, and suggest that the outflow can be described in terms of a very low-collimation bipolar outflow. Finally, we have also compared the present MIR results with NIR mapping from the Two Micron All Sky Survey (2MASS). These show that whilst the structures of the sources are comparable within these differing wavelength regimes, there are differences attributable to grain extinction and shock or fluorescently excited H2. [ABSTRACT FROM AUTHOR]

We present 3.6, 4.5, 5.8 and 8.0 μm photometry and mapping for 58 compact H ii regions identified using the Spitzer Galactic Legacy Infrared Midplane Survey Extraordinaire (GLIMPSE). These are used to investigate trends in the colours, magnitudes and structures of the sources, together with spatial variations in flux ratio. It is concluded that most of the sources are remarkably similar, and have comparable variations in flux ratio as a function of position within the shells, together with very narrowly defined ranges of colour index. Systematic variations of surface brightnesses S with harmonic mean size Θ(HARM) also imply that , where ; a result which may suggest that the widths of the emission zones are either more or less invariant, or increase with increasing source size. We note that the variation in longer wave flux ratios may imply the presence of polycyclic aromatic hydrocarbon (PAH) emission within large photodissociative regimes, evidence for which is also noted in colour imaging of the sources. The most intense 5.8 and 8 μm emission appears to be concentrated close to the interior ionization fronts, however, where fluorescent excitation of the PAH molecules and the number densities for the grain carriers are both likely to be at their greatest. [ABSTRACT FROM AUTHOR]

The bipolar planetary nebula NGC 650-1 has been imaged in Hα, Hβ, [N ii]λ6583 Å and [S ii]λλ6717+6731 Å. These results are used to map the variation of extinction over the interior regions of the shell, where we find evidence for a gradual increase in AV between the SW and NE limits of the central emission bar. It is argued that this is likely to arise from dust associated with the nebular envelope itself. We have also produced a map of electron densities over this region, and find evidence for marked variations in ne over a scale of ∼5 arcsec, a variation which is probably related to the clumpy emission structure observed in low-excitation images. We finally present contour mapping of mid-infrared Spitzer images of the source at 3.6, 4.5, 5.8 and 8 μm. These show that the central bar has a more or less uniform emission structure, although with evidence for condensations which are similar to, and in most cases coincidental with, comparable low-excitation structures noted in [N ii]. There is also evidence for an increase in 8/4.5 μm and 5.8/4.5 μm emission ratios with distance from the nucleus, and for an extension of 8 and 5.8 μm emission beyond the ionized regime; a trend which is attributed to strong polycyclic aromatic hydrocarbon band emission within the nebular photodissociative regime. [ABSTRACT FROM AUTHOR]

We present 3.6, 4.5, 5.8 and mapping, images and profiles for 13 Macquarie/Anglo-Australian Observatory (AAO)/Strasbourg (MASH) and MASH II planetary nebulae (PNe). Most of these sources have mid-infrared (MIR) morphologies which are similar to those observed in the visible, although there are differences attributable to polycyclic aromatic hydrocarbon (PAH) emission features, warm dust continua and a variety of ionic and molecular transitions. Such transitions also lead to the development of more extended haloes at longer MIR wavelengths, likely associated with photo-dissociative regimes (PDRs) about the primary ionized envelopes. It is noted that the colour characteristics of the envelopes, and the relative lack of detection of the sources in the MIR, point to the nebulae being appreciably evolved, a result which is in accordance with a prior analysis of Hα results. Finally, it is suggested that differences between the MIR colours of the MASH sources on the one hand, and of less evolved PNe on the other, may arise because of an evolution in the numbers of PAH-carrying grains within the PDRs, and/or variations in the far-ultraviolet (FUV) energy density of the stellar radiation fields. The tendency for fluxes to increase with increasing MIR wavelength probably arises from variations in PAH emission strengths, as well as from the contribution of broader dust continua. [ABSTRACT FROM AUTHOR]

The nature of the source G25.5+0.2 is open to considerable uncertainty, and it has variously been identified as being a young stellar outflow, an H ii region, a young supernova remnant and a planetary nebula. We present further Two-Micron All-Sky Survey (2MASS), Mid-course Space Experiment (MSX) and Spitzer near- (NIR) and mid-infrared (MIR) photometry and mapping in an attempt to clarify the properties of the source. It is apparent that the morphology varies appreciably with MIR wavelength and indicates the presence of a bipolar structure and probable circum-nebular torus. It is also noted that the 2MASS stellar photometry is quite disparate from that of earlier NIR measures and implies an appreciable variation in the brightness and colour of the central star. These two factors, the nuclear variability and bipolarity, combine to suggest the G25.5+0.2 may be identifiable as a symbiotic outflow. The nebular continuum peaks at wavelengths , and may be fitted using a fall-off in grain emissivity, together with a model in which the grains have temperatures and 130 K. An analysis of dust/gas mass ratios also implies that , depending upon the types of grains and temperatures involved. Such a range is typical of what is observed in planetary nebulae and symbiotic outflows. [ABSTRACT FROM AUTHOR]

We present images and photometry of a stellar ring-like structure G052.4−00.0 discovered during visual inspection of the Spitzer GLIMPSE Atlas. Although G052.4−00.0 may correspond to one of a large variety of sources, it is argued that it is most likely to be associated with an early-type supergiant at a distance of ∼8 kpc from the Sun. Where this is the case, then the radius of the ring would be of the order of ≈0.3 pc, comparable to those of similar structures about other supergiant stars, and the extinction would be of the order of ∼21 mag. [ABSTRACT FROM AUTHOR]

We have undertaken echelle spectroscopy and narrow-band line imaging of the bipolar planetary nebula M 1-8. This has permitted us to map the outflow in [N ii]λλ 6548+6583 Å, Hα, and in the v= 1–0 S(1) transition of H2 at λ 2.122 μm. It has also permitted us to acquire high-resolution spectra for [N ii]λ 6583 Å, Hα and He iiλ 6560 Å. Our observations support the results of a previous 2MASS analysis by two of the authors (J. P. Phillips and G. Ramos-Larios), and confirm that there is strong H2 emission outside of the ionized zone, as well as along the major axis of the outflow. Finally, we have investigated the spatial structure of the outflow in low and high excitation lines, and noted evidence for strong ionization stratification within the envelope of the source. We also note that major axis spectra show asymmetries attributable to outflow along the lobes, oriented at an angle i∼ 35°–40° to the line of sight. Asymmetries along the minor axis, by contrast, appear to be associated with the central collimating disc, and may be interpretable in terms of asymmetries in disc structure, or rotation at an angular velocity of Ω∼ 1.4 10−12 rad s−1. If the disc arises due to common-envelope evolution, then it seems that angular momentum constraints must be relatively tight, and can only be satisfied given fairly extreme physical assumptions (such as low disc mass, high primary star mass, a low distance to the source and so forth). [ABSTRACT FROM AUTHOR]

We have undertaken a mid-infrared (MIR) search for new planetary nebulae (PNe) using the Spitzer Space Telescope GLIMPSE Galactic plane survey. This has involved searching extant GLIMPSE data products for morphologically appropriate structures, and investigating sources having IRAS colours similar to those of Galactic PNe. We have found 12 sources which have a high probability of being high-extinction PNe, and which possess MIR and IRAS colours, and shell morphologies similar to those of previously identified Galactic nebulae. Calibrated mapping of these structures and profiles in all four of the IRAC bands (3.6, 4.5, 5.8 and ) suggests that many (if not all) of the nebulae possess at least two primary structures: an interior high surface brightness shell, corresponding to what is probably the primary ionized zone, and a much weaker halo extending to very much greater distances from the nucleus. These latter regimes are particularly evident at longer MIR wavelengths (5.8 and ), and it is probable that they trace the nebular photodissociative regimes, where emission derives from small-grain continua and/or polycyclic aromatic hydrocarbon molecular bands. This latter behaviour has also been noted in previous analyses of Galactic PNe. [ABSTRACT FROM AUTHOR]

Objective: To develop software infrastructure that will provide support for discovery, characterization, integrated access, and management of diverse and disparate collections of information sources, analysis methods, and applications in biomedical research.Design: An enterprise Grid software infrastructure, called caGrid version 1.0 (caGrid 1.0), has been developed as the core Grid architecture of the NCI-sponsored cancer Biomedical Informatics Grid (caBIG) program. It is designed to support a wide range of use cases in basic, translational, and clinical research, including 1) discovery, 2) integrated and large-scale data analysis, and 3) coordinated study.Measurements: The caGrid is built as a Grid software infrastructure and leverages Grid computing technologies and the Web Services Resource Framework standards. It provides a set of core services, toolkits for the development and deployment of new community provided services, and application programming interfaces for building client applications.Results: The caGrid 1.0 was released to the caBIG community in December 2006. It is built on open source components and caGrid source code is publicly and freely available under a liberal open source license. The core software, associated tools, and documentation can be downloaded from the following URL: https://cabig.nci.nih.gov/workspaces/Architecture/caGrid.Conclusions: While caGrid 1.0 is designed to address use cases in cancer research, the requirements associated with discovery, analysis and integration of large scale data, and coordinated studies are common in other biomedical fields. In this respect, caGrid 1.0 is the realization of a framework that can benefit the entire biomedical community. [ABSTRACT FROM AUTHOR]

Comet 73P/Schwassmann–Wachmann 3 made a close approach to Earth in the first half of 2006, during which its nucleus was observed to disintegrate into 80 or more fragments. We report the results of infrared mapping of fragment B on May 12, during which images were obtained in J, H and K′. The observations indicate the presence of strong variations in colour as a function of position within the comet, with the largest indices occurring close to the nucleus. This may be explainable in terms of scattering by grains having a mixture of sizes, and the influence of grain thermal emission within the K′ photometric band. There is a strong possibility that increased smaller grain scattering within the tail may arise as a result of the disintegration of aggregate particles. [ABSTRACT FROM AUTHOR]

We present 3.6-, 4.5-, 5.8- and 8.0-μm photometric mapping of 18 galactic planetary nebulae, based on observations taken with the Spitzer Space Telescope. These are shown to have morphologies which are sometimes quite different from those observed in the visible, with much of the emission arising outside the ionized shells. There is also evidence for a change in nebular sizes between the differing photometric bands. An analysis of mid-infrared (MIR) colours suggests that many nebulae have dust/polycyclic aromatic hydrocarbon (PAH) emission components, and it seems likely that longer wave MIR fluxes (in particular) are associated with PAH emission features. Such features are likely to be associated, in addition, with photodissociative regimes, where shock fragmentation of dust may lead to the replenishment of smaller PAH grains. Finally, we note that the source Ap 2–1 possesses a particularly interesting structure, and may represent a case in which the nebular shell is ploughing through an enveloping H ii region. Similarly, it appears that central emission in M 2–48 may arise from a warm and dusty collimating disc. [ABSTRACT FROM AUTHOR]

When male investment in mating varies with quality, reliable sexual signals may evolve. In many songbirds, testosterone mediates mating investment, suggesting that signals should be linked to testosterone production. However, because testosterone may change rapidly during behaviour such as territorial aggression and courtship, efforts to establish such a relationship have proved challenging. In a population of dark-eyed juncos, we measured individual variation in the production of short-term testosterone increases by injecting gonadotropin-releasing hormone (GnRH). We found a positive correlation between the magnitude of these increases and the size of a plumage ornament (‘tail white’) previously shown to be important for female choice and male–male competition. We then measured naturally elevated testosterone levels produced during male–male competition and found that they covaried with those induced by GnRH. We suggest that the association between tail white and testosterone increases may allow conspecifics to assess potential mates and competitors reliably using tail white. [ABSTRACT FROM AUTHOR]

An analysis is undertaken of the relation between dust/gas mass ratios and elemental abundances within planetary nebulae (PNe). It is found that MDUST/ MGAS is broadly invariant with abundance, and similar to the values observed in asymptotic giant branch (AGB)-type stars. However, it is noted that the masses of dust observed in low-abundance PNe are similar to the masses of heavy elements observed in the gas phase. This is taken to imply that levels of elemental depletion must be particularly severe, and extend to many more species than have been identified so far. In particular, given that levels of C and O depletion are likely to be large, then this probably implies that species such as Fe, S, Si and Mg are depleted as well. There is already evidence for depletion of Fe, Si and Mg in individual PNe. It follows that whilst quoted abundances may accurately reflect gas-phase conditions, they are likely to be at variance with intrinsic abundances in low ZN nebulae. Finally, we note that there appears to be a variation in dust/gas mass ratios with galactocentric distance, with gradient similar to that observed for several elemental abundances. This may represent direct evidence for a correlation between dust/gas mass ratios and nebular abundances. [ABSTRACT FROM AUTHOR]

We have used recent radiative transfer solutions for cavity-centred shells to investigate the prevalence of density gradients in Galactic ultra-compact H ii regions. We find that an analysis of 5 and 1.4 GHz data, taken from the recent compilation of Giveon et al., implies that ∼76 per cent of sources may have appreciable density gradients. It would also seem that the central cavities of these sources must be relatively small, with radii no greater than ∼20 per cent of those of the outer shells. The remainder of these sources are presumably homogenous, have much larger cavities, or possess reverse density gradients (densities which increase with increasing radius). A good fraction of the H ii regions also appear to have high brightness temperatures, implying mean electron temperatures of the order of . This value is higher than has been determined for other such sources. [ABSTRACT FROM AUTHOR]

Certain hydrodynamic models of planetary nebulae (PNe) suggest that their shells possess appreciable radial density gradients. However, the observational evidence for such gradients is far from clear. On the one hand, Taylor et al. claim to find evidence for radio spectral indices , a trend which is taken to imply a variation in most of their sample of PNe. On the other hand, Siódmiak & Tylenda find no evidence for any such variations in density; shell inhomogeneities, where they occur, are primarily attributable to ‘blobs or condensations’. It will be suggested that both of these analyses are unreliable, and should be treated with a considerable degree of caution. A new analysis within the plane will be used to show that at least 10–20 per cent of PNe are associated with strong density gradients. We shall also show that the ratio varies with nebular radius; an evolution that can be interpreted in terms of varying shell masses, and declining electron densities. [ABSTRACT FROM AUTHOR]

We present Two Micron All Sky Survey photometry for 216 symbiotic and possible symbiotic stars. This represents the most comprehensive near-infrared photometry for these sources which has been published to date. The results are used to define the statistics of S- and D-type stars; to investigate the photometric properties of Magellanic S-type symbiotics; and to define the possible evolution of D-type symbiotics within the J− H/ H− KS colour plane. It appears that the colours of D-type symbiotics are consistent with differing mass-loss rates d M/d t, provided that the grains have a silicate-like composition, and maximum temperatures of the order of ∼800 K. [ABSTRACT FROM AUTHOR]

Objectives: To compare the noise and vibration levels associated with three hand-held rock drills (pneumatic, hydraulic and electric) currently used in South African mines, and a prototype acoustically shielded self-propelled rock drill. [ABSTRACT FROM PUBLISHER]

Three sorghum × Sudangrass hybrids were planted in twelve 0.2-ha plots to test the effect of date of harvest and hybrid on plant maturity, DM yield, chemical composition, and in situ DM and fiber disappearance. Sweet Sunny Sue (a non-brown midrib (BMR) hybrid; nonBMR), NutriPlus BMR (a BMR hybrid; NP-BMR), and Dry Stalk BMR (a BMR hybrid; DS-BMR) were planted on 26 June 2003 at 22.4 kg of seed/ha. Beginning 34 d after planting, plant height and phenological growth stage were assessed weekly in 10 random, 0.5-m2 quadrats per plot. Plants were clipped to 2.5 cm in height and analyzed for CP, NDF, and ADF using near-infrared spectroscopy. Composite samples harvested from each plot on d 34, 48, and 63 were incubated in the rumen of 3 steers to determine the in situ disappearance of DM and NDF in a 3 × 3 Latin square. Forage yield was greater (P ≦ 0.02) for nonBMR than NP-BMR on d 41 and 55 and tended (P = 0.08) to be greater on d 48. The DS-BMR hybrid produced more (P = 0.04) forage DM than the NP-BMR on d 48. When DM yield was regressed on growth stage at harvest, BMR hybrids were predicted to produce 265 kg/ha more DM (P < 0.01) than nonBMR, at the late-boot stage. At all harvest dates, NDF concentrations were less (P ≦ 0.02) for BMR than nonBMR. The DS-BMR had greater (P ≦ 0.02) NDF concentrations than NP-BMR on d 41, 48, 55, and 63. Detergent fiber concentrations were predicted to be greater (P < 0.01) in nonBMR than BMR when regressed on growth stage at harvest, but the magnitude of the differences in fiber concentration diminished with growth stage. The A fractions of DM and NDF were greater (P < 0.01) and the C fraction was less (P < 0.01) for BMR hybrids than nonBMR. The B fraction of DM was not affected (P = 0.15) by hybrid type. The B fraction of NDF was not different (P = 0.28) on d 34 but was greater (P < 0.01) on d 48 and 63 for BMR than nonBMR. Effective degradability of NDF and DM was greater (P < 0.02) for BMR than nonBMR on all harvest dates. The A fraction of DM was less for DS-BMR than NP-BMR (P < 0.01), but the B and C fractions of NDF and DM did not differ (P > 0.13) between BMR hybrids. This research indicates that forage chemical composition and ruminal in situ disappearance are improved in the BMR sorghum × Sudangrass hybrids tested compared with the nonBMR. Yield reductions are commonly reported for BMR hybrids, but predicted DM yields in the current study were not reduced if harvested at a similar phenological growth stage. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the effect of species of cool-season annual grass on the growth of stocker cattle over 3 yr. In Exp. 1, the small grains (SG) oat (0), rye (R), and wheat (W), or combinations of SG and annual ryegrass (RG), were interseeded into Bermudagrass sod in a completely randomized design with a 3 × 2 factorial arrangement of treatments. In Exp. 2, RG was planted alone or with 0, R, triticale (T), or W in a completely randomized design. Pastures were planted in late October of each year, and seeding rates were 134.4 and 22.4 kg/ha for SG and RG, respectively. In Exp. 1, grazing was initiated on December 18. In Exp. 2, grazing was initiated on December 23 for SG pastures and January 21 or February 16 for RG pastures in yr 1 and on December 8 for all pastures in yr 2. Grazing was managed using the put-and-take method, in which additional calves were added as needed to maintain equal grazing pressure among pastures. In Exp. 1, no interactions (P ≥ 0.28) were detected, so the main effects of SG species and RG addition are discussed. From December 18 to March 12, there were no differences in ADG (P ≥ 0.17), whereas during the spring (from March 12 to May 7), addition of RG increased (P = 0.05) ADG. Using RG increased (P ≦ 0.01) animal grazing-days/hectare and BW gain/hectare. Wheat tended (P = 0.08) to increase BW gain/hectare compared with the other SG, and 0 tended (P = 0.09) to produce less BW gaimfhectare than the other SG. The treatment × year interaction was significant (P ≦ 0.05) in Exp. 2. In yr 1, no differences (P = 0.25) were observed for AUG from December 23 to March 8, but during the spring grazing period (from March 8 to May 5), ADG of calves grazing TRG was less (P ≦ 0.04) than that of those grazing RG, RRG, or WRG. The RRG combination produced more (P ≦ 0.03) BW gain/hectare than ORG, RG, or TRG and tended (P = 0.06) to produce more BW gain/hectare than WRG. The WRG combination produced more (P ≦ 0.05) BW gain/hectare than TRG and RG, and ORG tended (P = 0.09) to produce more BW gain/hectare than RG alone. Pastures planted to R or W produced more (P ≦ 0.05) BW gain/hectare than RG alone or T. During yr 2, there were no differences (P ≥ 0.44) in ADG, BW gain/hectare, or grazing-days/hectare. In conclusion, the choice of cool-season annual to establish is highly weather-dependent, but R and W are generally superior to other small grains, and RG is a necessary complement to SG when interseeding cool-season annuals into Bermudagrass sod. [ABSTRACT FROM AUTHOR]

We have used 2 Micron All Sky Survey (2MASS) mapping results to investigate the distribution of hot dust continua in 12 planetary nebulae (PNe). The nature of this emission is unclear, but it is possible that where the continuum is extended, as is the case for M 1-12 and NGC 40, then the grains concerned may be very small indeed. The absorption of individual photons by such grains may lead to sharp spikes in temperature, as has previously discussed for several other such outflows. Other sources (such as MaC 1-4, He 2-25, B1 2-1 and K 3-15) appear to be relatively compact, and the high temperatures observed are understandable in terms of more normal heating processes. It is possible that the grains in these cases are experiencing high radiant flux levels. Finally, it is noted that whilst the core of M 2-2 appears to show hot grain emission, this is less the case for its more extended envelope. The situation may, in this case, be similar to that of NGC 2346, in which much of the emission is located within an unresolved nucleus. Similarly, it is noted that in addition to hot dust and gas thermal continua, the emission in the interior of NGC 40 may be enhanced through rotational–vibrational transitions of H2, and/or the 2p3P0–2s3S transition of He i. [ABSTRACT FROM AUTHOR]

We note that H2 emitting planetary nebulae tend to have Zanstra temperatures . This is shown to be consistent with a large evolutionary lifetime, and the kinematic ages of the envelopes. Non-local thermodynamic equilibrium stellar atmospheric modelling also shows that levels of soft X-ray emission increase more rapidly than has previously been assumed, and are preferentially large in H2 emitting sources. It is suggested that this may hold the key to explaining the strengths of the H2 transitions. [ABSTRACT FROM AUTHOR]

We point out that many planetary nebulae (PNe) have large infrared indices ( H– KS), and that this is likely to result from the presence of hot grains, and/or H2 S(1) line emission at . We are able to identify two groups of sources associated with each of these mechanisms, both of which appear to possess distinct physical characteristics. One difference between these groups concerns the near-infrared dimensions of the sources. It appears that hot dust outflows frequently have sizes . Four of the sources are particularly extreme in this regard, and show emission extending well outside of the primary shells. We propose that this is likely to arise from high-temperature grains located in low-density haloes. The location of such grains at large distances from the central stars represents a challenge for any mechanism purporting to explain this phenomenon. The most likely explanation appears to be in terms of photon heating of very small grains. [ABSTRACT FROM AUTHOR]

Background. A decrease in the rate of human immunodeficiency virus (HIV) infection-related wasting has been reported in the era of highly active antiretroviral therapy (HAART). We investigated this concern in a hard- to-reach population of HIV-infected drug users in Miami, Florida. Methods. After informed consent was obtained, 119 HI V-infected drug users were administered questionnaires involving demographic, medical history, and food-security information. Blood samples were drawn for immunological and viral studies. HIV-related wasting over a period of ⩾6 months was defined as a body mass index of <18.5 kg/m², unintentional weight loss of ⩾10% over 6 months, or a weight of <90% of the ideal body weight. Results. The prevalence of HIV-related wasting was 17.6%. A significantly higher proportion of those who experienced wasting (81%) reported that there were periods during the previous month when they went for ⩾1 day without eating (i.e., food insecurity), compared with those who did not experience wasting (57%). Although a greater percentage of patients who experienced wasting were receiving HAART, their HIV RNA levels were more than twice as high (mean ± standard deviation [SD], 166,689 ± 238,002 copies/mL; median log HIV RNA level ± SD, 10.2 ± 2.7 log10 copies/mL) as those for the group that did not experience wasting (mean ± SD, 72,156 ± 149,080; median log HIV RNA level ± SD, 9.2 ± 2.3 log10 copies/mL). Participants who experienced wasting were more likely to be heavy alcohol drinkers and users of cocaine. In multivariate analysis that included age, sex, food security, alcohol use, cocaine use, viral load, and receipt of antiretroviral therapy, the only significant predictors of wasting were ⩾1 day without eating during the previous month (odds ratio [OR], 1.96; 95% confidence interval [CI], 1.18-3.26; P = .01) and viral load (OR, 1.64; 95% CI, 1.00-2.69; P = .05). Conclusions. HIV-related wasting continues to be common among HIV-infected drug users, even among HAART recipients. Food insecurity and viral load were the only independent predictors of wasting. The social and economic conditions affecting the lifestyle of HIV-infected drug users constitute a challenge for prevention and treatment of wasting. [ABSTRACT FROM AUTHOR]

It has recently been pointed out that a number of the methods used to determine planetary nebulae (PNe) distances may be appreciably in error. Whilst the scales of , and others are appropriate for higher radio brightness temperatures TB, those of Phillips and Daub are more relevant where TB is small. We note, in the following, that the absolute bolometric magnitudes of less-evolved PNe are likely to be similar. The mean value of can therefore be used to constrain PNe distances D, and confirm the distance scales for higher TB outflows. We have used this procedure to evaluate distances to a further 47 PNe, and we find that the mean values of are consistent with those of , , Phillips et al. (2004) and . They are, as expected, inconsistent with the lower TB scale of . [ABSTRACT FROM AUTHOR]

Objective: There has been a dramatic increase in the interest and practice of laparoscopic urology, with nephrectomy having become the commonest laparoscopic urological procedure. Compared with open nephrectomy, it results in reduced morbidity and shorter convalescence times while maintaining oncological safely. However, while these results predominately stem from institutions with well developed laparoscopic programmes, little is known about the results in centres that have newly adopted this technique. The introduction of a laparoscopic urological service at the Royal Halkimshire Hospital provided an opportunity to study these factors. Methods: Since the appointment in October 2000 of a urological surgeon (N Oakley) to develop the laparoscopic service, there have been over 200 laparoscopic procedures including 121 nephrectomies performed at this centre. Full details were collected for each of these cases, and in addition, compared with retrospective data for 50 open nephrectomies performed during the same time period. Results: With increased operator experience the median operative duration, complication, transfusion, and conversion rates significantly improved. While a learning curve was evident, the overall operative complication (9%) and conversion rates (6%) were low, in addition to patient morbidity (16.5%) and mortality (0%) rates, showing that this learning curve had no deleterious effects upon patient care. The median hospital stay was four days, which reduced to three with experience and was significantly shorter than for open nephrectomy at this institution (p =0.001). Conclusions: The development of a successful laparoscopic programme can be achieved with a comparatively short learning curve and without detriment to the patient provided the necessary steps are observed. [ABSTRACT FROM AUTHOR]

To compare the performance of steer calves managed under different stocking rates (SR, 3.7, 6.2,8.6, and 11.1 steers/ha for 140 d, χ11) and N fertilization rates (112, 224, and 336 kg of N/ha, χ12) in May 1996, 1997, and 1998, 72 steer calves (BW = 231 ± 2.5 kg) were assigned randomly to one of 12 0.81-hadallisgrass (51%)/common bermudagrass (32%) pastures. One-third of the fertilizer was applied in the form of ammonium nitrate in May, June, and August to achieve the prescribed totals. Treatments were separated using a polynomial regression equation: &#x03B3i = β0% + β1χ11 + β2χ12 + β11χ211 + β12χ212 + β12χi1χi2 + ϵI, with years as replicates. Within the range of the data, ADG and BW gain per steer were greatest at a stocking rate of 3.7 steers/ha and 336 kg/ha of N. Body weight gain per hectare peaked at 701 kg when cattle were stocked at 8.9 steers/ha and the pasture was fertilized with 336 kg/ha of N. The least cost of production was at a stocking rate of 3.7 steers/ha, with 112 kg/ha of fertilizer N applied, and the greatest cost of production was at a stocking rate of 11.1 steers/ha with 336 kg/ha of fertilizer N applied. Fertilization at 336 kg/ha of N produced the most profitable stocking rate at 7.3 steers/ha and re- turned $355.64. The optimal stocking rate for net return was 79, 81, and 82% of that for maximum BW gain per hectare for 112,224, and 336 kg/ha of N, respectively. Under the assumptions made in the financial analysis, these data show that the economically optimal carrying capacity of similar pastures can be increased with N fertilizer up to at least 336 kg/ha annually. [ABSTRACT FROM AUTHOR]

Planetary nebulae are known to possess a broad range of abundances, and these (with other characteristics) have been used to define five classes of outflow. Peimbert Type I sources, for instance, possess high N and He abundances, filamentary structures, and low mean scaleheights above the Galactic plane, whilst those of Type III have much lower abundances, high peculiar velocities, and belong to the Galactic thick disc. Apart from some rather ill-defined indications, however, very little is known concerning their mean physical, spatial, structural, kinematic and thermal characteristics. We have performed a comprehensive study of all of these properties, and find evidence for strong variations between the various Peimbert classes. Certain of these differences are consistent with Type I sources having the highest progenitor masses, although it seems that these nebulae also possess the lowest rms densities and 5-GHz brightness temperatures. The latter results are in conflict with a range of recent modelling. [ABSTRACT FROM AUTHOR]