Numerous Filaments Research Articles

A streamer behavior evolution during an applied voltage cycle in helium and argon atmospheric pressure plasma jets fed by DBD

The study describes the behavior of plasma streamer discharges in helium and argon atmospheric pressure plasma jets fed by dielectric barrier discharge with the specific AC voltage waveform, which has hundred-kHz oscillations deviated from the zero level. The equivalent electrical and gas feeding conditions for producing both helium and argon jets have been provided. The plasma jet in helium is shown to have a diffusive structure and is formed by guided ionization waves, whereas an argon plasma jet is formed by numerous filaments which can have several branches on their ends. Repetitive stepwise plasma bullet formation has been observed in He plasma jet, whereas random and stochastic branching of the streamer has been recorded in Ar plasma jet. Both types of streamers have an approximately equal maximum of their length but significantly differ with the lifetime: they exist for about 1 and almost 8 μs in the argon and helium plasma jets, correspondingly.

Energetic Submesoscale Dynamics in the Ocean Interior

AbstractSubmesoscale ocean processes, characterized by order-1 Rossby and Richardson numbers, are currently thought to be mainly confined to the ocean surface mixed layer, whereas the ocean interior is commonly assumed to be in quasigeostrophic equilibrium. Here, a realistic numerical simulation in the Antarctic Circumpolar Current, with a 1/48° horizontal resolution and tidal forcing, is used to demonstrate that the ocean interior departs from the quasigeostrophic regime down to depths of 900 m, that is, well below the mixed layer. Results highlight that, contrary to the classical paradigm, the ocean interior is strongly ageostrophic, with a pronounced cyclone–anticyclone asymmetry and a dominance of frontogenesis over frontolysis. Numerous vortices and filaments, from the surface down to 900 m, are characterized by large Rossby and low Richardson numbers, strong lateral gradients of buoyancy, and vigorous ageostrophic frontogenesis. These deep submesoscales fronts are only weakly affected by internal gravity waves and drive intense upward vertical heat fluxes, consistent with recent observations in the Antarctic Circumpolar Current and the Gulf Stream. As such, deep submesoscale fronts are an efficient pathway for the transport of heat from the ocean interior to the surface, suggesting the presence of an intensified oceanic restratification at depth.

Interspecific Differences in the Metabolic Rate, Gill Dimension and Hematology of Fish in an Amazonian Floodplain Lake

It has been hypothesized that respiratory physiology in fish is closely associated with ecological traits. Therefore, data on gill morphometrics (lamellae frequency, gill surface area and barrier thickness), metabolic rate (oxygen consumption) and blood oxygen capacity (hematology) were analyzed in several fish, including benthic, bentho-pelagic and pelagic species collected in an Amazon floodplain lake. Similar to other teleostean species, the 2nd and 3rd gill arches have numerous large filaments in both pelagic and benthic species, as these characteristics tend to increase the gill surface area. A large gill area (4 to 7 cm2 g-1, mass-specific) is associated with a high (100 to 300 mg O2 h-1 kg-1) routine oxygen consumption rate and has been observed in active pelagic swimmers, such as Cichla monoculus and Pygocentrus nattereri. Benthic dwelling fish (e.g., Pterygoplichthys pardalis and Sorubim lima) have low metabolic rates (20 to 50 mg O2 h-1 kg-1), small gill dimensions (2 to 3 cm2 g-1, mass-specific), low hemoglobin levels (3 to 5 g dL-1), reduced numbers of circulating red blood cells (1 to 2 Í106 mm-3) and low hematocrit values (25 to 35%) compared to pelagic species. These results demonstrated that pelagic fish have high routine oxygen consumption rates compatible with their large gill surface area and high blood oxygen capacity, whereas benthic species have low metabolic rates, small gill dimensions and reduced blood oxygen capacity.

First report of Dermatophilus congolensis infection in native Omani cattle.

Skin lesions were reported in a group of quarantined Omani native cattle for exportation purpose during January 2018. The skin lesions were reported in 17 animals out of 140 and were scattered over the head, neck, back and perineal region of the animals. Lesions varied from paint-brush matted hairs to wart-like lesions that are up to 2 cm in diameter. Skin scraping samples were obtained from the living animals and were directly stained with gram stain. Histologically, there was severe multifocal exudative dermatitis with hyperkeratosis. Dermis was infiltrated with neutrophils, mononuclear cells, and numerous branching filaments coccoid bodies. Bacterial culture on sheep blood agar revealed gray to white, beta hemolytic, raised and irregularly shaped colonies. Gram staining showed gram positive branching filaments with both transverse and longitudinal fragments formed from packs of coccoid cells confined with Dermatophilus congolensis. Animals were treated successfully with 3 doses of intra muscular injection of long-acting oxytetracycline with topical application of antibiotic spray. To the best of our knowledge, this is the first report of dermatophilosis in Omani cattle.

Star-forming content of the giant molecular filaments in the Milky Way

Context.Through observations numerous giant molecular filaments (GMFs) have been discovered in the Milky Way. Their role in the Galactic star formation and Galaxy-scale evolution of dense gas is unknown.Aims.We investigate systematically the star-forming content of all currently known GMFs. This allows us to estimate the star formation rates (SFRs) of the GMFs and to establish relationships between the SFRs and the GMF properties.Methods.We identified and classified the young stellar object (YSO) population of each GMF using multiwavelength photometry from near- to far-infrared. We estimated the total SFRs assuming a universal and fully sampled initial mass function and luminosity function.Results.We uniformly estimate the physical properties of 57 GMFs. The GMFs show correlations between the13CO line width, mass, and size, similar to Larson’s relations. We identify 36 394 infrared excess sources in 57 GMFs and obtain SFRs for 46 GMFs. The median SFR surface density (ΣSFR) and star formation efficiency (SFE) of GMFs are 0.62M⊙Myr−1pc−2and 1%, similar to the nearby star-forming clouds. The star formation rate per free-fall time of GMFs is between 0.002−0.05 with the median value of 0.02. We also find a strong correlation between SFR and dense gas mass that is defined as gas mass above a visual extinction of 7 mag, which suggests that the SFRs of the GMFs scale similarly with dense gas as those of nearby molecular clouds. We also find a strong correlation between the mean SFR per unit length and dense gas mass per unit length. The origin of this scaling remains unknown, calling for further studies that can link the structure of GMFs to their SF activity and explore the differences between GMFs and other molecular clouds.

Repeatable Interindividual Variation in Hypoxia Tolerance in the Gulf Killifish, Fundulus grandis.

The capacity of fishes to tolerate low oxygen (hypoxia) through behavioral and physiological adjustments varies among species in a fashion that correlates with oxygen availability in their natural habitats. Less is known about variation in hypoxia tolerance within a species, but it is expressly this interindividual variation that will determine which individuals will survive during severe hypoxia. Here, we measured aquatic surface respiration (ASR) and loss of equilibrium (LOE), two common indexes of hypoxia tolerance of fishes, in gulf killifish, Fundulus grandis, subjected to multiple trials of a highly reproducible hypoxia protocol over a period of 6-8 wk. The time and [Formula: see text] at the first occurrence of ASR and the time and [Formula: see text] at LOE differed significantly among individuals in a repeatable fashion. This interindividual variation in ASR and LOE was significantly correlated with general body and gill morphology. The time to ASR was shorter and the [Formula: see text] at ASR was higher for fish with greater mass. After correcting for mass, fish with longer or more numerous gill filaments had longer times to ASR or LOE, respectively. Fish in better condition factor (heavier for their length) had lower [Formula: see text] at LOE. Repeatable interindividual variation in hypoxia tolerance, if genetically based, could influence the capacity of species to adapt as their habitats become increasingly threatened by aquatic hypoxia.

Regularly Spaced Infrared Peaks in the Dusty Spirals of Messier 100

Abstract Spitzer Space Telescope Infrared Array Camera (IRAC) images of M100 show numerous long filaments with regularly spaced clumps, suggesting the associated cloud complexes formed by large-scale gravitational instabilities in shocked and accumulated gas. Optical images give no hint of this underlying regularity. The typical spacing between near-infrared clumps is ∼410 pc, which is ∼3 times the clump diameter, consistent with the fastest growing mode in a filament of critical line density. The IRAC magnitudes and colors of several hundred clumps are measured in the most obvious 27 filaments and elsewhere. The clump colors suggest that the dust is associated with diffuse gas, polycyclic aromatic hydrocarbon emission, and local heating from star formation. Neighboring clumps on the same filament have similar magnitudes. The existence of many clumps all along the filament lengths suggests that the ages of the filaments are uniform. The observations support a model where interstellar gas is systematically accumulated over lengths exceeding several kpc, forming spiral-like filaments that spontaneously collapse into giant clouds and stellar complexes. Optical wavelengths show primarily the irregular dust debris, H ii regions, and lingering star formation downstream from these primal formation sites.

A new equation for predicting settling velocity of solid spheres in fiber containing power-law fluids

Fiber containing power law fluids are widely used as drilling/fracturing fluids to improve wellbore cleaning efficiency or enhance proppant transport in the oil and gas industry. Understanding the settling behavior of solids in fibrous fluids is critical for designing and optimizing fiber containing fluids. In this paper, an new equation for predicting the settling velocity of solids in fiber containing power-law fluids is presented. Settling tests recorded by a high-speed camera were conducted, considering fiber concentration, sphere diameter, particle density and base fluid rheology. The microscopic observation shows that numerous filaments disperse in the base fluid, intercross together, and form the fiber network. The fiber network causes a minor change in the base fluid rheology, and reduces sphere settling velocity by exerting the mechanical drag, called fiber drag force to the settling sphere. To quantify the fiber drag force, a revised definition of the fiber drag coefficient is made and proved to be fit for spheres with different densities. The sum of fiber drag coefficient and viscous drag coefficient is called as total drag coefficient. A non-dimensional term that is the function of total drag coefficient is defined that is independent of the sphere settling velocity. Finally, the settling velocity equation is obtained by correlating the non-dimensional term versus the particle Reynolds number (0.002–416), fiber concentration(0.02%–0.10% by weight) and flow behavior index. The predicted settling velocity is in good agreement with the measurement, with an average relative difference of 12.49%. The key findings of this work are expected to provide a basis for better the application of fiber containing power-law fluids.

<div class="page" title="Page 1"><div class="layoutArea"><div class="column">Reinstatement of Phrix (Delesseriaceae, Rhodophyta) based on DNA sequence analyses and morpho-anatomical evidence</div></div></div>

Living material of a marine red alga consisting of a prostrate basal system and small erect blades was isolated from laboratory-incubated substratum collected in a sea cave at 7 m depth on Easter Island in the Southeast Pacific. The alga in culture was morphologically identified as Apoglossum gregarium (E.Y. Dawson) M.J. Wynne. Molecular analyses (rbcL, LSU, COI) revealed that this alga was not closely related to Apoglossum ruscifolium (Turner) J. Agardh, the generitype. It also was genetically and morphologically distinct from Paraglossum and other genera in the Delesseriaceae. Therefore, it is proposed that the genus Phrix J.G. Stewart be reinstated. Because the taxonomic synonym Membranoptera spatulata E.Y. Dawson has priority over Hypoglossum gregarium E.Y. Dawson, the binomial Phrix spatulata (E.Y. Dawson) comb. nov. is effected as the name for the sole species currently recognized in this genus of the Delesseriaceae (Rhodophyta). This is a new record of the species from Chile. The basal system in culture developed from numerous coalescent uniseriate filaments from which the blades arose and showed this isolate to be a male with spermatangial sori.

Rewilding Religion

This article follows just one of the numerous filaments that emerge from Schaefer’s proposition and its configuration: perception. The aim in not to purely analyse and critique Religious Affects: Animality, Evolution, and Power (2015), but rather to enter into an ‘animal dance’ with it. The discussion-dance seeks to contribute to the space deftly opened by Schaefer in which theoretical accounts of religious affect that exist ‘outside of language’ may be developed. Centrally, it asks: How do we perceive and represent the dance? Indeed, the case studies found in Religious Affects have already proffered a response to that question. This modest contribution aims to further explore how scholars may take account of elusive immateriality — forces, emotion, energy etc. — methodologically. In taking up this challenge the central focus is on the utility of embodied perception and the rendering of such knowledge in academic discourse.

An astrosphere around the blue supergiant κ Cas: possible explanation of its filamentary structure

High-resolution mid-infrared observations carried out by the Spitzer Space Telescope allowed one to resolve the fine structure of many astrospheres. In particular, they showed that the astrosphere around the B0.7 Ia star κ Cas (HD 2905) has a clear-cut arc structure with numerous cirrus-like filaments beyond it. Previously, we suggested a physical mechanism for the formation of such filamentary structures. Namely, we showed theoretically that they might represent the non-monotonic spatial distribution of the interstellar dust in astrospheres (viewed as filaments) caused by interaction of the dust grains with the interstellar magnetic field disturbed in the astrosphere due to colliding of the stellar and interstellar winds. In this paper, we invoke this mechanism to explain the structure of the astrosphere around κ Cas. We performed 3D magnetohydrodynamic modelling of the astrosphere for realistic parameters of the stellar wind and space velocity. The dust dynamics and the density distribution in the astrosphere were calculated in the framework of a kinetic model. It is found that the model results with the classical MRN (Mathis, Rumpl & Nordsieck 1977) size distribution of dust in the interstellar medium do not match the observations, and that the observed filamentary structure of the astrosphere can be reproduced only if the dust is composed mainly of big (μm-sized) grains. Comparison of the model results with observations allowed us to estimate parameters (number density and magnetic field strength) of the surrounding interstellar medium.

Macrobiotus polypiformis sp. nov., a new tardigrade (Macrobiotidae; hufelandi group) from the Ecuadorian Pacific coast, with remarks on the claw abnormalities in eutardigrades

From a moss sample collected in the Manabí Province in Ecuador, we extracted 96 specimens of a new species of eutardigrade. No eggs were found. In order to obtain eggs, an in vitro culture was prepared. In total, 136 specimens (including ten simplex), one exuvia and 44 eggs (including two with embryos) of the new species were obtained. In addition to the traditional taxonomic description with morphometrics, light and scanning microscopy imaging, we also provide nucleotide sequences of three nuclear (18S rRNA, 28S rRNA, ITS-2) and one mitochondrial (COI) DNA fragments of the new species. Macrobiotus polypiformis sp. nov. belongs to the hufelandi group and is most similar to Ma. paulinae Stec, Smolak, Kaczmarek & Michalczyk, 2015, but differs from it mainly by the lack of dorso-lateral patches of granulation on the cuticle, egg processes with longer and more numerous filaments and in some morphometric characters of both eggs and adults. Moreover, we provide a short discussion on the modifications/abnormalities of the claws in eutardigrades and the possible consequences on the taxonomic status of Mesobiotus armatus (Pilato & Binda, 1996), suggesting its consideration as species inquirenda (with uncertain taxonomic status).

Optical detection of nanometric thermal fluctuations to measure the stiffness of rigid superparamagnetic microrods

The rigidity of numerous biological filaments and crafted microrods has been conveniently deduced from the analysis of their thermal fluctuations. However, the difficulty of measuring nanometric displacements with an optical microscope has so far limited such studies to sufficiently flexible rods, of which the persistence length ([Formula: see text]) rarely exceeds 1 m at room temperature. Here, we demonstrate the possibility to probe 10-fold stiffer rods by a combination of superresolutive optical methods and a statistical analysis of the data based on a recent theoretical model that predicts the amplitude of the fluctuations at any location of the rod [Benetatos P, Frey E (2003) Phys Rev E Stat Nonlin Soft Matter Phys 67(5):051108]. Using this approach, we report measures of [Formula: see text] up to 0.5 km. We obtained these measurements on recently designed superparamagnetic [Formula: see text]40-[Formula: see text]m-long microrods containing iron-oxide nanoparticles connected by a polymer mesh. Using their magnetic properties, we provide an alternative proof of validity of these thermal measurements: For each individual studied rod, we performed a second measure of its rigidity by deflecting it with a uniform magnetic field. The agreement between the thermal and the magnetoelastic measures was realized with more than a decade of values of [Formula: see text] from 5.1 m to 129 m, corresponding to a bending modulus ranging from 2.2 to 54 (×[Formula: see text] Jm). Despite the apparent homogeneity of the analyzed microrods, their Young modulus follows a broad distribution from 1.9 MPa to 59 MPa and up to 200 MPa, depending on the size of the nanoparticles.

Intermittent energy dissipation by turbulent reconnection

AbstractMagnetic reconnection—the process responsible for many explosive phenomena in both nature and laboratory—is efficient at dissipating magnetic energy into particle energy. To date, exactly how this dissipation happens remains unclear, owing to the scarcity of multipoint measurements of the “diffusion region” at the sub‐ion scale. Here we report such a measurement by Cluster—four spacecraft with separation of 1/5 ion scale. We discover numerous current filaments and magnetic nulls inside the diffusion region of magnetic reconnection, with the strongest currents appearing at spiral nulls (O‐lines) and the separatrices. Inside each current filament, kinetic‐scale turbulence is significantly increased and the energy dissipation, E′ ⋅ j, is 100 times larger than the typical value. At the jet reversal point, where radial nulls (X‐lines) are detected, the current, turbulence, and energy dissipations are surprisingly small. All these features clearly demonstrate that energy dissipation in magnetic reconnection occurs at O‐lines but not X‐lines.

Tube fossils from gossanites of the Urals VHMS deposits, Russia: Authigenic mineral assemblages and trace element distributions

The occurrence, types, morphology, and mineralogical characteristics of tube microfossils were studied in gossanites from twelve VHMS deposits of the Urals. Several types of tube microfossils were recognized, including siboglinids, polychaetes and calcerous serpulids, replaced by a variety of minerals (e.g. hematite–quartz, hematite–chlorite, carbonate–hematite) depending on the nature of the substrate prior to the formation of the gossanites. Colonial hematite tube microfossils (~150μm across,1–2mm long) are composed of hematitic outer and inner walls, and may exhibit a cellular structure within their cavities. Spherical forms are saturated with Fe-oxidizing bacteria inside the tubes – probably analogues of trophosomes. Colloform stromatolitic outer wall surfaces are characterized by the presence of numerous interlaced filaments of hematite (2–3μm diameter, up to 1–2mm long). Between tube microfossils, the hematitized cement contains bundles of hematitized filaments with structures similar to the hyphae of fungi. Hematite–chlorite tube microfossils are scattered in gossanites, mostly as biological debris. They are typically 30 to 300μm in diameter and 1 to 5mm long. The layered structure of their tube walls is characterized by hematite–quartz and chlorite layers. Abundant filamentous bacteria coated by glycocalix and chlorite stromatolite are associated with hematite–chlorite tubes. The carbonate–hematite tube microfossils (up to 300μm across, 2–3mm long) occur in carbonate-rich gossanites. The tubes are characterized by fine (~10μm thick) walls of hematite and cavities dominated by relatively dark carbonate or hematite. Carbonates may be present both in walls and cavities. Stromatolite-like leucoxene or hematite–carbonate aggregates were also found in association with tubes. Randomly oriented filaments are composed of ankerite. Single filaments are composed of individual cells, typically smaller than 100nm across, similar to that of magnetotactic bacteria.Three dimensional tomographic images of all types of tube microfossils demonstrate a clear wavy microlayering from outer and inner walls, which may reflect segmentation of the tube worms. The traces of burrowing or fragments of glycocalix with relict spheres are typical of tube microfossils from gossanites.The carbon isotopic composition of carbonates associated with tube microfossils from hematite–quartz, hematite–carbonate, and hematite–chlorite gossanites average−7.2, − 6.8, –22.8‰, PDB, respectively. These values are indicative of a biogenic origin for the carbonates. The oxygen isotopic composition of these carbonates is similar in all three gossanite types averaging +13.5, +14.2, +13.0‰ (relative to SMOW), and indicative of active sulfate reduction during the diagenetic (and anadiagenetic) stages of the sediments evolution. The trace element characteristics of hematite from tube microfossils are characterized by high contents of following trace elements (average, ppm): Mn (1529), As (714), V (540), W (537), Mo (35), and U (5). Such high contents are most likely the result of metal and metalloid sorption by fine particles of precursor iron hydroxides during the oxidation of sulfides and decomposition of hyaloclasts via microbially-mediated reactions.

Dissociation and Re-Aggregation of Multicell-Ensheathed Fragments Responsible for Rapid Production of Massive Clumps of Leptothrix Sheaths

Species of the Fe/Mn-oxidizing bacteria Leptothrix produce tremendous amounts of microtubular, Fe/Mn-encrusted sheaths within a few days in outwells of groundwater that can rapidly clog water systems. To understand this mode of rapid sheath production and define the timescales involved, behaviors of sheath-forming Leptothrix sp. strain OUMS1 were examined using time-lapse video at the initial stage of sheath formation. OUMS1 formed clumps of tangled sheaths. Electron microscopy confirmed the presence of a thin layer of bacterial exopolymer fibrils around catenulate cells (corresponding to the immature sheath). In time-lapse videos, numerous sheath filaments that extended from the periphery of sheath clumps repeatedly fragmented at the apex of the same fragment, the fragments then aggregated and again elongated, eventually forming a large sheath clump comprising tangled sheaths within two days. In this study, we found that fast microscopic fragmentation, dissociation, re-aggregation and re-elongation events are the basis of the rapid, massive production of Leptothrix sheaths typically observed at macroscopic scales.

Submesoscale currents in the northern Gulf of Mexico: Deep phenomena and dispersion over the continental slope

This study examines the mesoscale and submesoscale circulations along the continental slope in the northern Gulf of Mexico at depths greater than 1000m. The investigation is performed using a regional model run at two horizontal grid resolutions, 5km and 1.6km, over a 3year period, from January 2010 to December 2012.Ageostrophic submesoscale eddies and vorticity filaments populate the continental slope, and they are stronger and more abundant in the simulation at higher resolution, as to be expected. They are formed from horizontal shear layers at the edges of highly intermittent, bottom-intensified, along-slope boundary currents and in the cores of those currents where they are confined to steep slopes. Two different flow regimes are identified. The first applies to the De Soto Canyon that is characterized by weak mean currents and, in the high-resolution run, by intense but few submesoscale eddies that form near preferentially along the Florida continental slope. The second is found in the remainder of the domain, where the mean currents are stronger and the circulation is highly variable in both space and time, and the vorticity field is populated, in the high-resolution case, by numerous vorticity filaments and short-lived eddies.Lagrangian tracers are deployed at different times along the continental shelf below 1000m depth to quantify the impact of the submesoscale currents on transport and mixing. The modeled absolute dispersion is, on average, independent of horizontal resolution, while mixing, quantified by finite-size Lyapunov exponents and vertical relative dispersion, increases when submesoscale processes are present. Dispersion in the De Soto Canyon is smaller than in the rest of the model domain and less affected by resolution. This is further confirmed comparing the evolution of passive dye fields deployed in De Soto Canyon near the Macondo Prospect, where the Deepwater Horizon rig exploded in 2010, and at the largest known natural hydrocarbon seep in the northern Gulf, known as GC600, located a few hundred kilometers to the west of the rig wellhead.

GIANT Hα NEBULA SURROUNDING THE STARBURST MERGER NGC 6240*

ABSTRACT We revealed the detailed structure of a vastly extended Hα-emitting nebula (“Hα nebula”) surrounding the starburst/merging galaxy NGC 6240 by deep narrow-band imaging observations with the Subaru Suprime-Cam. The extent of the nebula is ∼90 kpc in diameter and the total Hα luminosity amounts to L Hα ≈ 1.6 × 1042 erg s−1. The volume filling factor and the mass of the warm ionized gas are ∼10−4–10−5 and ∼5 × 108 M ⊙, respectively. The nebula has a complicated structure, which includes numerous filaments, loops, bubbles, and knots. We found that there is a tight spatial correlation between the Hα nebula and the extended soft-X-ray-emitting gas, both in large and small scales. The overall morphology of the nebula is dominated by filamentary structures radially extending from the center of the galaxy. A large-scale bipolar bubble extends along the minor axis of the main stellar disk. The morphology strongly suggests that the nebula was formed by intense outflows—superwinds—driven by starbursts. We also found three bright knots embedded in a looped filament of ionized gas that show head-tail morphologies in both emission-line and continuum, suggesting close interactions between the outflows and star-forming regions. Based on the morphology and surface brightness distribution of the Hα nebula, we propose the scenario that three major episodes of starburst/superwind activities, which were initiated ∼102 Myr ago, formed the extended ionized gas nebula of NGC 6240.

Nocardia Brain Abscess in a Patient of Lung Cancer

Abstract: Nocardia infection is reported to increase in numbers due to the increment of immunocompromised patients. The insidious onset of Nocardia infection and the complexity of clinical presentation in Central Nervous System (CNS) often will be a challenge to the clinicians. The traditional drug of choice for the Nocardia infection is sulfamethoxazole/trimethoprim. However, as the resistance to the drug increases, other antibiotics should be considered to render alternatives. Linezolid could be the one of the options. We report a case of brain abscess of Nocardia asteroids in a 71-year-old woman of lung cancer. Keywords: Brain abscess; Lung cancer; Nocardia infection Clinical Presentation; A 71-year-old woman of lung cancer, adenocarcinoma, left lower lobe, T3NxM1b, with lung to lung, liver, and brain metastasis had began to receive oral target therapy with Irresa and the whole brain radiotherapy (WBRT) was recommended. Chest X-rayrevealed shrinkage of the tumor dramatically after Irresa. Agitation and inappropriate behavior seized her, which had been attributed to brain metastasis and complication of WBRT. However, vague opacity of both lung fields increased and antibiotics had been used, but her condition deteriorated to respiratory failure. Endotracheal intubation and mechanical ventilation were used, and then she was transferred to respiratory intensive care unit. Magnetic resonance imaging of brain showed one brain abscess with diameter of 11 mm over the right occipital area (Figure 1). Careful neurologic examination was done, but it revealed neither defect of visual fields nor deficit of motor function. Empirical antibiotics were given for 2 weeks. Computed tomography of brain revealed the increasing abscess in diameter to 16 mm. Biological examination of the sampled fluid through the craniotomy revealed Nocardia asteroids. Intravenous (IV) sulfamethoxazole/trimethoprim was given, but low grade fever persisted. Meanwhile, IV linezolid was introduced to cover Nocardia infection of the brain for 3 weeks and she became clear gradually. Oral linezolid was used for 10 weeks. Nocardia is the soil-borne aerobic bacteria of the order actinomycetales, a gram-positive numerous non-motile filaments and partially acid-fast, mainly occurring in the lungs, brain or skin. It is an opportunistic pathogen usually through inhalation or direct cutaneous inoculation, so primary infection is pulmonary or cutaneous and brain abscess is the characteristic lesion of CNS infection through hematogenous spread [1]. The incidence of Nocardia brain abscess is only 2%. The mortality of Nocardia brain abscess is 20-55% in immunocompromised and immunocompetent patients, respectively [2]. It is difficulty and delayed in diagnosis and management because of paucity of clinical and laboratory signs of infection and insidious manifestations [3]. Nocardiosis is increasingly being diagnosed in the recent years due to increasing number of immunocompromised hosts and improvement of modality in the detection of Nocardia species in clinical laboratories. The first-line therapy of Nocardia infection is sulphonamides/trimethoprim and linezolid is an alternative drug if allergy or resistance [4].

DISCOVERY OF AN APPARENT HIGH LATITUDE GALACTIC SUPERNOVA REMNANT

Deep H$\alpha$ images of a faint emission complex 4.0 x 5.5 degrees in angular extent and located far off the Galactic plane at l = 70.0 degrees, b=-21.5 degrees reveal numerous thin filaments suggestive of a supernova remnant's shock emission. Low dispersion optical spectra covering the wavelength range 4500 - 7500 A show only Balmer line emissions for one filament while three others show a Balmer dominated spectrum along with weak [N I] 5198, 5200 A, [O I] 6300, 6364 A, [N II] 6583 A, [S II] 6716, 6731 A and in one case [O III] 5007 A line emission. Many of the brighter H$\alpha$ filaments are visible in near UV GALEX images presumably due to C III] 1909 A line emission. ROSAT All Sky Survey images of this region show a faint crescent shaped X-ray emission nebula coincident with the portion of the H$\alpha$ nebulosity closest to the Galactic plane. The presence of long, thin Balmer dominated emission filaments with associated UV emission and coincident X-ray emission suggests this nebula is a high latitude Galactic supernova remnant despite a lack of known associated nonthermal radio emission. Relative line intensities of the optical lines in some filaments differ from commonly observed [S II]/H$\alpha$ > 0.4 radiative shocked filaments and typical Balmer filaments in supernova remnants. We discuss possible causes for the unusual optical SNR spectra.