Dynamic HPLC on chiral stationary phases: a powerful tool for the investigation of stereomutation processes

Dynamic HPLC on enantioselective stationary phases has become a well-established technique to investigate chiral molecules with internal motions that result in stereoinversion and occur on the time scale of the separation process. Kinetic parameters for the on-column interconversion phenomena can be extracted from experimental peak profiles by computer simulation or by direct calculation methods. The technique has been used in a wide range of temperatures and is complementary in scope to dynamic NMR spectroscopy

Are leukocyte and platelet abnormalities and complete blood count ratios potential prognostic markers in canine sepsis?

Background: Sepsis is a common disease in which early diagnosis and prognosis assessment are the main aims in order to arrange a prompt and effective treatment. Objectives: (1) To compare leukogram parameters (WBC, segmented and band neutrophils,lymphocytes,monocytes),plateletcount(PLT),meanplateletvolume(MPV), and some leukocyte/platelet ratio such as NLR, NBNLR, PLR, and MLR between dogs with systemic inflammatory response syndrome (SIRS) and sepsis. (2) To investigate any difference in the trend of these latter parameters between survivors and non-survivors septic dogs. Animals: 57 dogs with confirmed sepsis and 57 dogs with non-septic SIRS. Methods: A review of the medical records was conducted in order to find dogs with sepsis. Sepsis was defined as the presence of an infectious focus with fulfillment of systemic inflammatory response syndrome criteria (SIRS). Septic dogs had to have a CBC at admission and another CBC within 48h from the previous timepoint. Purebreds with CBC breed-related abnormalities were excluded, together with dogs without confirmed sepsis and dogs with only a single CBC. NLR, NBNLR, PLR, and MLR were calculated. Univariate analysis of all blood parameters studied was assessed between SIRS and septicdogs. Generalized Estimating Equations models for repeated measures were used to test if the blood parameters studied were modified between survivors and non-survivors in the septic group. Results: Septic dogs had lower median segmented neutrophils count and NLR compared to SIRSdogs (p=0.02andp=0.04, respectively).Lastly,septicdogs hada higherprevalenceoftoxicneutrophilthanSIRSdogs(p=0.01).Wefoundthatfora1-unit increase of PLR and MLR, the risk of death increased by 50.5 and 60%, respectively. Conclusion and Clinical Importance: Evaluation of NLR at hospital admission may be a useful marker of inflammation, although it showed low sensitivity in differentiating SIRS and septic dogs. The monitoring of some CBC parameters, especially PLR and MLR may be useful in the establishment of prognosis in septic dogs

Multi-wavelength characterisation of z~2 clustered, dusty star forming galaxies discovered by Planck

(abridged) We report the discovery of PHz G95.5-61.6, a complex structure detected in emission in the Planck all-sky survey that corresponds to two over-densities of high-redshift galaxies. This is the first source from the Planck catalogue of high-z candidates that has been completely characterised with follow-up observations from the optical to the sub-millimetre domain. Herschel/SPIRE observations at 250, 350 and 500 microns reveal the existence of five sources producing a 500 microns emission excess that spatially corresponds to the candidate proto-clusters discovered by Planck. Further observations at CFHT in the optical bands (g and i) and in the near infrared (J, H and K_s), plus mid infrared observations with IRAC/Spitzer (at 3.6 and 4.5 microns) confirm that the sub-mm red excess is associated with an over-density of colour-selected galaxies. Follow-up spectroscopy of 13 galaxies with VLT/X-Shooter establishes the existence of two high-z structures: one at z~1.7 (three confirmed member galaxies), the other at z~2.0 (six confirmed members). This double structure is also seen in the photometric redshift analysis of a sample of 127 galaxies located inside a circular region of 1'-radius containing the five Herschel/SPIRE sources, where we found a double-peaked excess of galaxies at z~1.7 and z~2.0 with respect to the surrounding region. These results suggest that PHz G95.5-61.6 corresponds to two accreting nodes, not physically linked to one another, embedded in the large scale structure of the Universe at z~2 and along the same line-of-sight. In conclusion, the data, methods and results illustrated in this pilot project confirm that Planck data can be used to detect the emission from clustered, dusty star forming galaxies at high-z, and, thus, to pierce through the early growth of cluster-scale structures.Comment: 15 pages, 13 figures. Accepted for publication in Astronomy and Astrophysic

Recent star formation in clusters of galaxies: extreme compact starbursts in A539 and A634

We report on the detection of two Halpha-emitting extreme compact objects from deep images of the Abell 634 and Abell 539 clusters of galaxies at z ~ 0.03. Follow up long slit spectroscopy of these two unresolved sources revealed that they are members of their respective clusters showing HII type spectra. The luminosity and the extreme equivalent width of Halpha+[NII] measured for these sources, together with their very compact appearance, has raised the question about the origin of these intense starbursts in the cluster environment. We propose the compact starburst in Abell 539 resulted from the compression of the interstellar gas of a dwarf galaxy when entering the cluster core; while the starburst galaxy in Abell 634 is likely to be the result of a galaxy-galaxy interaction, illustrating the preprocessing of galaxies during their infall towards the central regions of clusters. The contribution of these compact star-forming dwarf galaxies to the star formation history of galaxy clusters is discussed, as well as a possible link with the recently discovered early-type ultra-compact dwarf galaxies. We note that these extreme objects will be rarely detected in normal magnitude-limited optical or NIR surveys, mainly due to their low stellar masses (of the order of 10^6 solar masses), whereas they will easily show up in dedicated Halpha surveys given the high equivalent width of their emission lines.Comment: Accepted for publication in the Astronomical Journal. 31 pages, 10 fig

Near-Infrared Adaptive Optics Imaging of the Central Regions of Nearby Sc Galaxies. II. NGC 247 and NGC 2403

J, H, and K' images obtained with the Canada-France-Hawaii Telescope adaptive optics system are used to investigate the star-forming histories of the central regions of the Sc galaxies NGC 247 and NGC 2403. The brightest resolved red stars within 15 arcsec of the nucleus of each galaxy are red supergiants, indicating that the central few hundred parsecs of these galaxies experienced star formation within the last ~ 0.1 Gyr. However, when averaged over Gyr time scales, the star-forming histories of the inner disks of these galaxies have been remarkably similar, as expected if the long-term evolution of disks is defined by local characteristics such as mass density. It is demonstrated that NGC 247 and NGC 2403, like M33, harbour nuclear star clusters with stellar contents that differ from the surrounding central light concentrations. The nucleus of NGC 2403 is significantly bluer than that of the other two galaxies and the K-band surface brightnesses near the centers of NGC 247 and NGC 2403 are 1 -- 2 mag per square arcsec lower than in M33. Finally, it is noted that young or intermediate-age nuclear star clusters are a common occurence in nearby spirals, indicating that nuclear star formation in these objects is either continuous or episodic on time scales of 0.1 - 1 Gyr.Comment: 27 pages of text and 14 figures; to appear in the Astronomical Journa

Erythrogram patterns in dogs with chronic kidney disease

Anemia is considered a common finding in dogs with chronic kidney disease (CKD), typically as normochromic, normocytic, and non-regenerative. Although anemia can occur at any CKD IRIS (International Renal Interest Society) stage, its severity is related with the loss of kidney function. The aim of the present study was to retrospectively evaluate quantitative and morphological abnormalities of the erythrogram in dogs at different CKD IRIS stages. A total of 482 CBCs from 3648 initially screened were included in the study. Anemia was present in 302/482 (63%) dogs, in the majority of which it was normochromic, normocytic, and non-regenerative (295/302; 98%). The number of reticulocytes was <60,000/mu L in the majority of dogs (248/295; 84%), with a correlation between poor regeneration rate and progression of CKD (p = 0.0001). The frequency of anemia significantly differed (p = 0.0001) among the IRIS stages: 108/231 (47%) in IRIS 2, 77/109 (71%) in IRIS 3, and 117/142 (82%) in IRIS 4. Dogs at IRIS stages 3 and 4 were more likely to have moderate to severe anemia, compared to dogs at IRIS stage 2 (p = 0.0001). Anisocytosis was the most frequent morphological abnormality (291/482; 60%), whereas the presence of poikilocytosis showed an association with progression of IRIS stages (p = 0.009). Among different morphological abnormalities, the frequency of fragmented red blood cells and Howell-Jolly bodies showed a significant association with the progression of CKD. Anemia was a frequent finding in CKD dogs, mostly associated with none to poor regeneration rate. Similar to human medicine, advanced CKD stages are more frequently characterized by morphological alterations, such as fragmented red blood cells and Howell-Jolly bodies, which may suggest a more severe condition of reduced bone marrow activity and microangiopathy

PACS photometry of the Herschel Reference Survey - Far-infrared/sub-millimeter colours as tracers of dust properties in nearby galaxies

We present Herschel/PACS 100 and 160 micron integrated photometry for the 323 galaxies in the Herschel Reference Survey (HRS), a K-band-, volume-limited sample of galaxies in the local Universe. Once combined with the Herschel/SPIRE observations already available, these data make the HRS the largest representative sample of nearby galaxies with homogeneous coverage across the 100-500 micron wavelength range. In this paper, we take advantage of this unique dataset to investigate the properties and shape of the far-infrared/sub-millimeter spectral energy distribution in nearby galaxies. We show that, in the stellar mass range covered by the HRS (8<log(M*/Msun)<12), the far-infrared/sub-millimeter colours are inconsistent with a single modified black-body having the same dust emissivity index beta for all galaxies. In particular, either beta decreases, or multiple temperature components are needed, when moving from metal-rich/gas-poor to metal-poor/gas-rich galaxies. We thus investigate how the dust temperature and mass obtained from a single modified black-body depend on the assumptions made on beta. We show that, while the correlations between dust temperature, galaxy structure and star formation rate are strongly model dependent, the dust mass scaling relations are much more reliable, and variations of beta only change the strength of the observed trends.Comment: 26 pages, 8 figures, 2 tables. Accepted for publication in MNRA

The Herschel Virgo Cluster Survey: IV. Resolved dust analysis of spiral galaxies

We present a resolved dust analysis of three of the largest angular size spiral galaxies, NGC 4501 and NGC 4567/8, in the Herschel Virgo Cluster Survey (HeViCS) Science Demonstration field. Herschel has unprecedented spatial resolution at far-infrared wavelengths and with the PACS and SPIRE instruments samples both sides of the peak in the far infrared spectral energy distribution (SED).We present maps of dust temperature, dust mass, and gas-to-dust ratio, produced by fitting modified black bodies to the SED for each pixel. We find that the distribution of dust temperature in both systems is in the range ~19 - 22 K and peaks away from the centres of the galaxies. The distribution of dust mass in both systems is symmetrical and exhibits a single peak coincident with the galaxy centres. This Letter provides a first insight into the future analysis possible with a large sample of resolved galaxies to be observed by Herschel.Comment: Letter accepted for publication in A&A (Herschel special issue

The far-infrared view of M87 as seen by the Herschel Space Observatory

The origin of the far-infrared emission from the nearby radio galaxy M87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We observed M87 with PACS and SPIRE as part of the Herschel Virgo Cluster Survey (HeViCS). We compare the new Herschel data with a synchrotron model based on infrared, submm and radio data to investigate the origin of the far-infrared emission. We find that both the integrated SED and the Herschel surface brightness maps are adequately explained by synchrotron emission. At odds with previous claims, we find no evidence of a diffuse dust component in M87.Comment: 4 pages, 2 figures, proceedings IAU Symposium 275 (Jets at all scales