Numerous Clumps Research Articles

MUSE observations of the blue compact dwarf galaxy Haro 14

Investigations of blue compact galaxies (BCGs) are essential to advancing our understanding of galaxy formation and evolution. BCGs are low-luminosity, low-metallicity, gas-rich objects that form stars at extremely high rates, meaning they are good analogs to the high-redshift star-forming galaxy population. Being low-mass starburst systems, they also constitute excellent laboratories in which to investigate the star formation process and the interplay between massive stars and their surroundings. This work presents results from integral field spectroscopic observations of the BCG Haro 14 taken with the Multi Unit Spectroscopic Explorer (MUSE) at the Very Large Telescope in wide-field adaptive optics mode. The large MUSE field of view (1′×1′ = 3.8 × 3.8 kpc2 at the adopted distance of 13 Mpc) enables simultaneous observations of the central starburst and the low-surface-brightness host galaxy, which is a huge improvement with respect to previous integral field spectroscopy of BCGs. From these data we built galaxy maps in continuum and in the brightest emission lines. We also generated synthetic broad-band images in the VRI bands, from which we produced color index maps and surface brightness profiles. We detected numerous clumps spread throughout the galaxy, both in continuum and in emission lines, and produced a catalog with their position, size, and photometry. This analysis allowed us to study the morphology and stellar populations of Haro 14 in detail. The stellar distribution shows a pronounced asymmetry; the intensity peak in continuum is not centered with respect to the underlying stellar host but is displaced by about 500 pc southwest. At the position of the continuum peak we find a bright stellar cluster that with Mv = −12.18 appears as a strong super stellar cluster candidate. We also find a highly asymmetric, blue, but nonionizing stellar component that occupies almost the whole eastern part of the galaxy. We conclude that there are at least three different stellar populations in Haro 14: the current starburst of about 6 Myr; an intermediate-age component of between ten and several hundred million years; and a red and regular host of several gigayears. The pronounced lopsidedness in the continuum and also in the color maps, and the presence of numerous stellar clusters, are consistent with a scenario of mergers or interactions acting in Haro 14.

AN UNUSUAL CASE OF ACUTE EOSINOPHILIC PNEUMONIA IN OLD AGE

TOPIC: Allergy and Airway TYPE: Medical Student/Resident Case Reports INTRODUCTION: Acute eosinophilic pneumonia/pneumonitis (AEP) is a rare respiratory illness characterized by eosinophil accumulation in the pulmonary interstitium and airspaces.Due to limited research done in older population, there is delayed and underdiagnosis in patients above age 40.Here we present a unique case of a 96-year-old man with AEP. CASE PRESENTATION: A 96-year-old lifetime non-smoker male with a history of hypertension, DVT on therapeutic enoxaparin presented to the hospital from a nursing home with a productive cough and increasing shortness of breath.He was found to be saturating at 80% on 4 liters of oxygen. Patient had a fever of 100.1F.Physical exam was significant for bilateral diminished breath sounds.His chest x-ray revealed worsening bilateral pulmonary infiltrates since his last admission with pneumonia last month.He was started on empiric antibiotics and High flow oxygen.CT chest showed bilateral ground glass opacities with increased interstitial thickening.Blood cultures, respiratory pathogen panel, SARS-COV2 PCR were negative. The patient's eosinophils increased to 11.7% with a progressive decline in neutrophil count. The bronchoalveolar lavage showed presence of numerous clumps of eosinophils. Patient was diagnosed with AEP and started on methylprednisolone 80 mg twice daily. Antibiotics were stopped and patient's status improved with continuous steroid treatment. Patient improved and was discharged on steroid taper. DISCUSSION: AEP is an idiopathic entity commonly associated with smoking, medications, allergic diathesis and parasitic infections. Furthermore, individuals between 20-40 years of age are most commonly affected. It causes IL-5 release and eosinophils accumulation, resulting in the release of toxic proteins and lipid mediators that promote a pro inflammatory reaction. Eosinophil counts may be normal on presentation, as seen in this case. Symptomatic AEP resembles pneumonia and While diagnosing AEP, it is important to exclude other disorders such as asthma or other atopic illnesses as these also respond to corticosteroids. Gold standard diagnosis of AEP is bronchoscopy with BAL which reveals eosinophilia (>25%). Treatment of AEP requires eliminating the inciting factor and initiating corticosteroids. While there are no clear guidelines on the optimal dosing of corticosteroids, there is evidence to suggest that high-dose IV steroids is effective in patients requiring mechanical intubation, whereas low dose oral prednisone is efficient in patients with minimal hypoxia. CONCLUSIONS: Our case here is unique as it highlights the occurrence of AEP in old age in the absence of associated factors. It is prudent to be vigilant of leukocyte trends in patients with recent history of pneumonia as not to misdiagnose and to consider other possible etiologies, such as AEP.If identified and treated appropriately, the disease has favorable outcomes with no long term sequalae. REFERENCE #1: Rhee CK, Min KH, Yim NY, Lee JE, Lee NR, Chung MP, Jeon K. Clinical characteristics and corticosteroid treatment of acute eosinophilic pneumonia. Eur Respir J. 2013 Feb;41(2):402-9. doi: 10.1183/09031936.00221811. Epub 2012 May 17. PMID: 22599359. REFERENCE #2: Pope-Harman, Amy L.;Davis, Bruce W.;Allen, Elizabeth D.;Christoforidis, John A.;Allen, James N. Acute Eosinophilic Pneumonia A Summary of 15 Cases and Review of the Literature, Medicine: November 1996 - Volume 75 - Issue 6 - p 334-342 DISCLOSURES: No relevant relationships by MohammadAsim Amjad, source=Web Response No relevant relationships by Ajinkya Buradkar, source=Web Response No relevant relationships by Kashyap Kela, source=Web Response No relevant relationships by Pooja Kharbanda, source=Web Response No relevant relationships by jacob miller, source=Web Response No relevant relationships by Princy Shah, source=Web Response

On the problems and prospects of native flora conservation in culture: from the experience of Samara University Botanical Garden

The information on the experience of preserving rare natural flora species ex situ is presented in the article.The largest amount of research conducted relates to herbaceous plants. For Juniperus sabina L., an extremely raregymnosperm plant of the Samara region, numerous clumps have been formed in the Botanical Garden, including somefrom local origin material. There is experience of successful reintroduction of both grassy and woody species (juniper).

Dusty clumps in circumbinary discs

ABSTRACT Recent observations have revealed that protoplanetary discs often exhibit cavities and azimuthal asymmetries such as dust traps and clumps. The presence of a stellar binary system in the inner disc regions has been proposed to explain the formation of these structures. Here, we study the dust and gas dynamics in circumbinary discs around eccentric and inclined binaries. This is done through two-fluid simulations of circumbinary discs, considering different values of the binary eccentricity and inclination. We find that two kinds of dust structures can form in the disc: a single horseshoe-shaped clump, on top of a similar gaseous over-density; or numerous clumps, distributed along the inner disc rim. The latter features form through the complex interplay between the dust particles and the gaseous spirals caused by the binary. All these clumps survive between one and several tens of orbital periods at the feature location. We show that their evolution strongly depends on the gas–dust coupling and the binary parameters. Interestingly, these asymmetric features could in principle be used to infer or constrain the orbital parameters of a stellar companion – potentially unseen – inside the inner disc cavity. Finally, we apply our findings to the disc around AB Aurigae.

P.18.12 Histological and magnetic resonance imaging findings of Vastus Lateralis in Myotonic Dystrophies: Do they match up?

In myotonic dystrophy type 1 (DM1), MRI shows a characteristic pattern of skeletal muscle involvement, and data are usually in line with the clinical presentation. In contrast, myotonic dystrophy type 2 (DM2) patients often show discrepancies between their clinical phenotype and MRI. Systematic data on MRI abnormalities and their histological correlates are not available to date. We analyzed Vastus Lateralis biopsies, corresponding 3T MRI, and clinical data in 1 DM1 (f, 150–200 CTGs; MIRS IV; ages at biopsy/MRI: 49/50 y) and 6 DM2 patients (f/m:3/3). In DM2, mean ages at biopsy and subsequent MRI examinations were 53.7+/−12.2 y and 57.7+/−13.3 y, respectively. 3 female DM2 patients had pathological MRI results indicative of fatty degeneration: 2 patients showed moderate fatty changes, 1 patient had a complete fibroadipose tissue replacement. The corresponding histological findings included increased fiber size variation, type I fiber predominance, increased numbers of internal nuclei, numerous pyknotic nuclear clumps, acid phosphatase-positive sarcoplasmic granules in normal appearing and/or degenerative fibers, and widespread fatty tissue replacement in all 3 patients, and results correlated well with the extent of MRI changes. Further 3 DM2 patients had normal MRI, however also showed histological abnormalities which were milder and included type I fiber predominance, type II fiber atrophy, an increase of internal nuclei, and numerous pyknotic nuclear clumps but no fatty degeneration. In DM1, MRI of Vastus Lateralis was normal. The histological findings were in line and showed only mild variations in fiber size and few nuclear clumps. In DM, histological and imaging findings correlated well with the clinical data on muscle strength of knee extensors. We conclude that MRI most reliably reflected fatty tissue replacement in vivo. In contrast, changes in fiber type distribution, abnormal position of myonuclei, and numerous nuclear clumps did not show MRI correlates.

In vivo cell‐scale imaging of the human retina by adaptive optics

AbstractDiagnosis and monitoring of retinal diseases, the most important causes of blindness in developed countries, is largely based on accurate imaging of the retina. We have been using a flood imaging, commercially available AO camera (rtx1 from ImagineEye) to examine a variety of retinal diseases. Geographic atrophy can be detected at a very early stage under the form of patches of depigmented RPE filled with numerous clumps of melanin. Time‐lapse imaging show the progression of atrophy at a very small spatial and temporal scale, as well as the motion of melanin clumps within and outside atrophic areas. Diabetic microaneurysms can be distinguished from hemorrages. Epiretinal membranes can be observed under the form of small star‐like hyperreflective spots. Finally, parietal remodelling of small arteries following arterial hypertension can be detected, which may provide a novel quantitative biomarker. To sum up, while AO imaging was originally used for photoreceptor imaging, its scope is now extending. AO fundus imaging will probably establish itself as a reference methodology for early detection and monitoring of a variety of retinal diseases.

What is your diagnosis? Preputial mass in a ferret

: A 7-year-old neutered male polecat-type ferret (Mustela putorius furo) was presented for evaluation of a cutaneous mass close to the preputial orifice. Cytologic examination of a fine-needle aspirate revealed numerous large clumps of amorphous pink mucinous material and numerous large clumps of slightly pleomorphic epithelial cells. The cells were arranged in papillary structures, palisades, and loosely cohesive sheets with a vaguely honeycomb appearance. Occasional acinar formations were also seen. The cells had moderate to large amounts of finely granular gray to gray-blue cytoplasm. The cells were round to wispy and elongated, with indistinct borders. Often, anuclear cytoplasmic clumps were seen free in the background or adjacent to intact cells. Nuclei were round to oval and usually off-center. Chromatin was finely stippled and contained 1-3 indistinct nucleoli. Anisokaryosis and anisocytosis were moderate. Binucleated cells were noted occasionally. The cytologic features were consistent with a carcinoma of probable apocrine origin. Histopathologic examination supported a diagnosis of secretory apocrine adenocarcinoma of the preputial skin. Secretory apocrine adenocarcinomas of the prepuce are seen relatively frequently in ferrets, although their cytologic appearance has not been described widely. These neoplasms carry a poor prognosis although prompt surgical removal with wide and deep surgical margins and adjunctive radiotherapy may improve survival.

Topology of HiGas Distribution in the Large Magellanic Cloud

We have analyzed the H I aperture synthesis image of the Large Magellanic Cloud (LMC), using an objective and quantitative measure of topology to understand the H I distribution, which hosts a number of holes and clumps of various sizes, in the interstellar medium. The H I distribution shows different topologies at four different chosen scales. At the smallest scales explored (19-29 pc), the H I mass is distributed in such a way that numerous clumps are embedded on top of a low-density background. At larger scales, from 73 to 194 pc, it shows a generic hole topology. These holes might have been formed mainly by stellar winds from hot stars. At scales from 240 to 340 pc, slightly above the disk scale height of the gaseous disk, major clumps in the H I map change the distribution to have a slight clump topology. These clumps include the giant cloud associations in the spiral arms and the thick filaments surrounding superholes. At the largest scales studied (390-485 pc), the hole topology is present again. Responsible for the hole topology at this scale are a few superholes that seem to be mainly associated with supernova explosions in the outer disk. The gaps between the bar and the spiral arms have a minor effect on the topology at this scale.

A cholesterol-enriched diet induces ultrastructural changes in retinal and macroglial rabbit cells

The purpose of this study was to ascertain whether the excess of cholesterol in rabbits induces ultrastructural retinal changes similar to those observed in human age-related macular degeneration (AMD). New Zealand rabbits were divided into two groups: Control (GO; n = 10), fed standard diet for 8 months; hypercholesterolemic (G1; n = 10), fed with 0.5% cholesterol-enriched diet for 8 months. Eyes were processed for transmission electron microscopy (TEM) and immunohistochemistry (anti-glial fibrillary acidic protein, GPAP). In comparison with GO, G1 exhibited alterations in all the retinal layers that were more intense in areas overlying altered retinal pigment epithelium (RPE). RPE changes showed no preferential location. In G1, Bruch's membrane was thicker as a result particle build-up in the collagen layers; the cytoplasm of RPE showed dense bodies, debris from cell membranes, vacuoles and numerous clumps of lipids; necrosis and apoptosis were detected in different retinal layers; Müller cells and astrocytes were reactive with instances of apoptosis and necrosis; some Müller cells filled up the empty spaces left by degenerated neurons in all retinal layers; some Müller cell nuclei were displaced to the nerve-fiber layer (NFL); epiretinal perivascular astrocytes contained drops of lipids; the NFL had very few astrocytes and the basal membranes of capillaries in the NFL was thicker. Excess cholesterol induces ultrastructural changes in the rabbit retina similar to those in human AMD. Given that lipid intake is most dependent on food composition, dietary regimen could help induce or prevent retinal disease.

The Origin of Structures in Wolf-Rayet Winds: FUSE Observations of WR 135

We report the detection with FUSE of strong, highly blueshifted absorption features appearing in the absorption troughs of practically all major P Cygni profiles in the presumably single Wolf-Rayet star WR 135. These features also appear in the shock-sensitive O VI λλ1032, 1038 doublet, coincident both in time and in velocity space with the rest of the lower ionization species. Choosing between two alternative interpretations (large-scale, coherent structures vs. localized, random shocks), we favor the latter. The absolute value of the velocity as well as the velocity dispersion in the shocked region, the density of the shocked gas, and the timescales of the observed variability allow us to relate the observed shocks to the incidence of numerous overdense clumps (blobs) in the wind of a hot, massive star.

Proper Motions of the HH 47 Jet Observed with theHubble Space Telescope

We present a proper-motion study of the shock waves within the classic stellar jet HH 47 based on Hubble Space Telescope (HST) Hα and [S II] images of the region taken over two epochs. Individual knots within the jet and in the bow shock/Mach disk working surface of HH 47A move significantly in the 5 yr that separate the images, and the excellent spatial resolution of HST makes it possible to measure the proper motions with enough precision to easily observe differential motions throughout the flow. The bright portion of the jet emerges at 375 ± 25 from the plane of the sky with an average velocity of 300 km s-1. Dynamical ages of the shock waves in the jet range from a few decades for knots recently ejected by the source to ~1300 yr for the faint extended bow shock HH 47D. The jet curves, but motions of knots in the jet are directed radially away from the exciting source, and velocity variability in the flow drives the shock waves that heat the jet internally. The jet orientation angle varies with time by about 15° and currently points to the northwestern portion of a cavity outlined by a reflection nebula, where a quasi-stationary shock deflects the jet. The major working surface HH 47A is more complex than a simple bow shock/Mach disk and contains numerous clumps that move relative to one another with velocities of ~±40 km s-1. Small clumps or instabilities affect the Mach disk, and dense clumps may move all the way through the working surface to cause the bumpy morphology seen at the bow shock. A localized area between the bow shock and Mach disk varies significantly between the two sets of images.

Evidence for transient clumps and gas chemical evolution in the CS core of L673

We present FCRAO maps as well as combined BIMA and FCRAO maps of the high density molecular emission towards the CS core in the L673 region. With the FCRAO telescope, we mapped the emission in the CS(2-1), C34S(2-1), HCO+(1-0), and H13CO+(1-0) lines. The high density molecular emission, which arises from a filamentary structure oriented in the NW-SE direction, shows clear morphological differences for each molecule. We find that HCO+ has an extremely high optical depth, and that the H13CO+ emission is well correlated with submm sources. The BIMA and FCRAO combined maps recover emission from a lot of other structure which was previously undetected or only marginally detected, and show an overall aspect of a filamentary structure connecting several intense clumps. We found a total 15 clumps in our combined data cube, all of them resolved by our angular resolution, with diameters in the 0.03-0.09 pc range. We find a clear segregation between the northern and southern region of the map: the northern section shows the less chemically evolved gas and less massive but more numerous clumps, while the southern region is dominated by the largest and most massive clump, and contains the more evolved gas, as traced by emission of late-time molecules. We find that the derived clump masses are below the virial mass, and that the clumps masses become closer to the virial mass when they get bigger and more massive. This supports the idea that these clumps must be transient, and only the more massive ones have a chance to last long enough to form stars. The clumps we detect are probably in an earlier evolutionary stage than the ``starless cores'' reported recently in the literature. Only the most massive one has properties similar to a ``starless core''.

Clumpy filaments of the Chamaeleon I cloud: C$\mathsf{^{18}}$O mapping with the SEST

The Chamaeleon  dark cloud (Cha ) has been mapped in C 18 O( J = 1−0) with an angular resolution of 1 � using the SEST telescope. The large scale structures previously observed with lower spatial resolution in the cloud turn into a network of clumpy filaments. The automatic Clumpfind routine developed by Williams et al. (1994) is used to identify individual clumps in a consistent way. Altogether 71 clumps were found and the total mass of these clumps is 230 M� . The dense de- tected with the NANTEN telescope (Mizuno et al. 1999) and the very cold cores detected in the ISOPHOT serendipity survey (Toth et al. 2000) form parts of these filaments but decompose into numerous clumps. The filaments are preferentially ori- ented at right angles to the large-scale magnetic field in the region. We discuss the cloud structure, the physical characteristics of the clumps and the distribution of young stars. The observed clump mass spectrum is compared with the predictions of the turbulent fragmentation model of Padoan & Nordlund (2002). Agreement is found if fragmentation has been driven by very large-scale hypersonic turbulence, and if by now it has had time to dissipate into modestly supersonic turbulence in the inter- clump gas. According to numerical simulations, large-scale turbulence should have resulted in filamentary structures as seen in Cha . The well-oriented magnetic field does not, however, support this picture, but suggests magnetically steered large-scale collapse. The origin of filaments and clumps in Cha  is thus controversial. A possible solution is that the characterization of the driving turbulence fails and that in fact different processes have been effective on small and large scales in this cloud.

AVLA search for embedded young stellar objects and protostellar candidates in L1630

Five molecular cloud cores in L1630 have been observed with the VLA in C configuration at a wavelength of 3.5 cm. These cores were identified in molecular line emission by a previous study, and contain numerous clumps which are excellent candidates for sites of low-mass star formation. To a 5σ limit of 0.1 mJy, corresponding to an 8.4-GHz luminosity of 1.9 × 1016 erg s−1 Hz−1 (uncorrected for primary beam attenuation), most (>75 per cent) of the clumps within these cores do not have an associated radio continuum source. Of the three likely associations, two were discovered in previous surveys of LBS 23 (HH 24–26), one of which (SSV 61) shows evidence for radio variability, while the third source is spatially coincident with one of the clumps in LBS 18 and may be a new class 0 protostar candidate. Another new discovery is that HH 26IR is probably detected at the 4σ level. Radio emission has also been detected from two of the early-type stars exciting the NGC 2068 reflection nebula (HD 38563C and S). These results are in agreement with earlier work which proposes that, in (the northern part of) L1630, a large fraction of the molecular gas is not directly involved with star formation at the current epoch, although there is evidence that low-mass star formation is in the early stages at a number of locations. A tentative suggestion is that perhaps only young stellar objects in the earliest and latest phases of protostellar evolution exhibit detectable radio continuum emission. The earliest emission may be due to bremsstrahlung from an ionized jet, which declines as a result of a decreasing accretion rate or outflow efficiency. The later emission is due to gyrosynchrotron processes arising as a consequence of a magnetic field in the vicinity of the star—disc interface. Alternatively, a combination of the source geometry and optical depth may be responsible for such an apparent correlation. Further observations of a larger sample are required to test whether this correlation is seen in a wider view of low-mass star formation.

Detection of centimeter-sized meteoroid impact events in Saturn's F ring.

Voyager images reveal that three prominent clumps in Saturn's F ring were short-lived, appearing rapidly and then spreading and decaying in brightness over periods of approximately 2 weeks. These features arise from hypervelocity impacts by approximately 10-centimeter meteoroids into F ring bodies. Future ring observations of these impact events could constrain the centimeter-sized component of the meteoroid population, which is otherwise unmeasurable but plays an important role in the evolution of rings and surfaces in the outer solar system. The F ring's numerous other clumps are much longer lived and appear to be unrelated to impacts.

NICMOS 2 Micron Continuum and H[TINF]2[/TINF] Images of OMC-1

The core of OMC-1 has been imaged with the Near-Infrared Camera and Multiobject Spectrometer (NICMOS) on board the Hubble Space Telescope at 02 resolution in 1% filters at 2.12 and 2.15 μm, revealing intricate structures in both continuum and shocked molecular hydrogen line emission. Numerous H2-emitting clumps surrounding the BN/KL region have been resolved for the first time, several of which exhibit prototypical bow-shock morphologies with V-shaped tips. We interpret these to be lower excitation analogs of similar structures ~2' northwest of the core observed with ground-based telescopes. Many of the elongated H2 structures and bow-shock features appear to radiate outward from a region within a few arcseconds of radio source I, which suggests that the H2 energetics are dominated by one or more outflow sources in this region. However, the orientations of some features are unrelated to this apparent outflow pattern. The deeply embedded, suspected outflow source I remains undetected at 2 μm, although two faint new continuum sources have been detected within ~1'' of it. The newly resolved H2 features with bow-shock morphologies are located in regions previously identified as bow shocks by highly blueshifted components in their line profiles. In contrast, regions of H2 emission that are diffuse in the NICMOS image have broad, smooth line profiles. Several continuum features have an arclike appearance, which suggests interactions of winds with the ambient medium. At least 40 stellar or protostellar continuum sources have been detected, including at least one proplyd and four pairs of binary stars.

Histopathology of retained bovine fetal membranes

Placentomes were obtained from 20 cows with retained placenta (9 following normal birth, 5 after abortion and 6 with dystocia), and this material was examined by light microscopy. Histologic changes that were consistently seen in placentomes of cows with retained placenta after normal birth included vascular changes (edema, thrombosis and vasculitis) and the presence of numerous clumps of bacterialcolonies in the connective tissue of the caruncles and cotyledons. Only a few binucleate cells were seen in these cases. In placentomes obtained from cows with retained placenta after abortion, there were instances of focal necrosis of the fetal villi and the presence of variable numbers of binucleate cells. Vascular changes and numerous clumps of bacterial colonies in the caruncles and cotyledons were also noted. The changes in placentomes obtained from cows with retained placenta and dystocia included the presence of numerous binucleate cells, infiltration of polymorphonuclear cells in the connective tissue of both the fetal and maternal villi, vascular changes, and the presence of extensive necrosis and numerous clumps of bacterial colonies. Significant differences (P < 0.05) were encountered in the number of binucleate cells in the various groups. Binucleate cells appear to be involved in the process of placental separation in cows with retained placenta.

Cardiac Tamponade in Chronic Myelomonocytic Leukemia: A Case Report

Serous effusion is a rare complication of chronic myelomonocytic leukemia. We present a patient with chronic myelomonocytic leukemia who developed a massive pericardial effusion with cardiac tamponade as early manifestations. Numerous clumps of monocytes were observed in the effusion. The patient obtained rapid relief following the intravenous administration of etoposide (100 mg daily for 5 days). Few reports have documented details of such a case.

The H II region surrounding LK H-alpha 101 and small-scale structure in the nearby atomic hydrogen

view Abstract Citations (17) References (10) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The H II Region Surrounding LkH alpha 101 and Small-Scale Structure in the Nearby Atomic Hydrogen Dewdney, P. E. ; Roger, R. S. Abstract New VLA observations of the H II region surrounding Lk H-alpha 101 and of the fine-scale structure in the extended H I cloud associated with the region are presented. The H II region measures about 0.3 pc in overall diameter, comprises 0.09 solar mass, and shows evidence of a substantial density gradient. The H I emission is characterized by a prominent ridge on the north side of the H II region and by numerous clumps of emission extending to radii between 1 and 2 pc. This distance is significantly less than the radius of the total H I cloud as revealed by lower resolution observations and may represent the extent of the penetration of the UV-driven dissociation front into dense molecular concentrations. Close to the star the advancement of the dissociation into such clumps may be abetted by the process of 'multiple pumping' in the Lyman bands. This process also accounts for the formation of a substantial H I zone around a relatively young H II region. The expected shocked shell of H I outside the ionization boundary was not detected. Publication: The Astrophysical Journal Pub Date: August 1986 DOI: 10.1086/164414 Bibcode: 1986ApJ...307..275D Keywords: Early Stars; H Alpha Line; H Ii Regions; Hydrogen Atoms; Nebulae; Stellar Spectra; Astronomical Maps; Atmospheric Ionization; Continuous Radiation; Gray Scale; Line Spectra; Astrophysics; NEBULAE: H II REGIONS; NEBULAE: INDIVIDUAL NGC NUMBER: NGC 1579; STARS: EMISSION-LINE; STARS: INDIVIDUAL ALPHANUMERIC: LKH ALPHA 101 full text sources ADS | data products SIMBAD (2)

Cytochemical staining of the endoplasmic reticulum and glycogen in mouse anterior pituitary cells.

The endoplasmic reticulum (ER) and glycogen in secretory cells of anterior pituitary glands from control and fasted mice were investigated ultrastructurally using cytochemical staining techniques. Potential enzyme cytochemical markers for the ER included glucose-6-phosphatase (G6Pase) and nucleoside diphosphatase (NDPase) activities. Presumptive glycogen particles were identified in tissue postfixed in 1% osmium tetroxide-1.5% potassium ferrocyanide or in ultrathin sections poststained with periodic acid-thiocarbohydrazide-silver proteinate. The ER appeared to be related structurally and cytochemically to the nuclear envelope and cis Golgi saccules. Similar relationships between the ER and the trans Golgi saccules or GERL were not observed. In anterior pituitary glands from control mice, G6Pase activity was prominent within the lumen of the ER, nuclear envelope, and cis Golgi saccules of all cells; reaction product was absent in the trans Golgi saccules and in GERL. G6Pase activity was sparse to non-existent in anterior pituitary cells from fasted mice. The cytochemical reaction utilizing the Gomori lead capture method indicated that G6Pase in anterior pituitary cells may function as a phosphohydrolase for converting glucose-6-phosphate to glucose. Cytochemical localization of NDPase activity was not evident in the ER; reaction product was localized consistently in one or two trans Golgi saccules and occasionally in GERL and nascent secretory granules. Presumptive glycogen particles in each of the different secretory cell types from control mice appeared as 20-30 nm wide, electron-dense particles scattered as single entities throughout the cytoplasm. Anterior pituitary glands from fasted mice exhibited conspicuous and numerous clumps of glycogen particles in addition to scattered particles in all cell types except corticotrophs, which appeared to be devoid of glycogen. Glycogen particles were absent in anterior pituitary cells incubated in a medium containing diastase. Our results suggest that in anterior pituitary cells of the mouse: 1) the phosphohydrolytic activity of G6Pase is a reliable cytochemical marker for the ER; 2) the ER is associated morphologically and cytochemically with the cis face but not with the trans face of the Golgi apparatus or with GERL; 3) some glucose-6-phosphate, a possible substrate for G6Pase in vivo, may be derived indirectly from glycogen stores; and 4) modulations in G6Pase activity and glycogen storage during fasting may reflect an alteration in energy metabolism.