A new method for spatially resolving the turbulence driving mixture in the ISM with application to the Small Magellanic Cloud

Turbulence plays a crucial role in shaping the structure of the interstellar medium. The ratio of the three-dimensional density contrast ($\sigma_{\rho/\rho_0}$) to the turbulent sonic Mach number ($\mathcal{M}$) of an isothermal, compressible gas describes the ratio of solenoidal to compressive modes in the turbulent acceleration field of the gas, and is parameterised by the turbulence driving parameter: $b=\sigma_{\rho/\rho_0}/\mathcal{M}$. The turbulence driving parameter ranges from $b=1/3$ (purely solenoidal) to $b=1$ (purely compressive), with $b=0.38$ characterising the natural mixture (1/3~compressive, 2/3~solenoidal) of the two driving modes. Here we present a new method for recovering $\sigma_{\rho/\rho_0}$, $\mathcal{M}$, and $b$, from observations on galactic scales, using a roving kernel to produce maps of these quantities from column density and centroid velocity maps. We apply our method to high-resolution HI emission observations of the Small Magellanic Cloud (SMC) from the GASKAP-HI survey. We find that the turbulence driving parameter varies between $b\sim 0.3$ and $b\sim 1.0$ within the main body of the SMC, but the median value converges to $b\sim0.51$, suggesting that the turbulence is overall driven more compressively ($b>0.38$). We observe no correlation between the $b$ parameter and HI or H$\alpha$ intensity, indicating that compressive driving of HI turbulence cannot be determined solely by observing HI or H$\alpha$ emission density, and that velocity information must also be considered. Further investigation is required to link our findings to potential driving mechanisms such as star-formation feedback, gravitational collapse, or cloud-cloud collisions.Comment: 20 pages, 16 figures, accepted to MNRA

WALLABY Pilot Survey: Hydra Cluster Galaxies UV and HI morphometrics

Galaxy morphology in atomic hydrogen (HI) and in the ultra-violet (UV) are closely linked. This has motivated their combined use to quantify morphology over the full H i disk for both H i and UV imaging. We apply galaxy morphometrics: Concentration, Asymmetry, Gini, M20 and Multimode-Intensity-Deviation statistics to the first moment-0 maps of the WALLABY survey of galaxies in the Hydra cluster center. Taking advantage of this new HI survey, we apply the same morphometrics over the full HI extent on archival GALEX FUV and NUV data to explore how well HI truncated, extended ultraviolet disk (XUV) and other morphological phenomena can be captured using pipeline WALLABY data products. Extended HI and UV disks can be identified relatively straightforward from their respective concentration. Combined with WALLABY HI, even the shallowest GALEX data is sufficient to identify XUV disks. Our second goal is to isolate galaxies undergoing ram-pressure stripping in the H i morphometric space. We employ four different machine learning techniques, a decision tree, a k-nearest neighbour, a support-vector machine, and a random forest. Up to 80% precision and recall are possible with the Random Forest giving the most robust results.Comment: 17 figures, 12 figures, 7 tables, accepted by MNRA

Chromatic periodic activity down to 120 MHz in a Fast Radio Burst

Fast radio bursts (FRBs) are extragalactic astrophysical transients whose brightness requires emitters that are highly energetic, yet compact enough to produce the short, millisecond-duration bursts. FRBs have thus far been detected between 300 MHz and 8 GHz, but lower-frequency emission has remained elusive. A subset of FRBs is known to repeat, and one of those sources, FRB 20180916B, does so with a 16.3 day activity period. Using simultaneous Apertif and LOFAR data, we show that FRB 20180916B emits down to 120 MHz, and that its activity window is both narrower and earlier at higher frequencies. Binary wind interaction models predict a narrower periodic activity window at lower frequencies, which is the opposite of our observations. Our detections establish that low-frequency FRB emission can escape the local medium. For bursts of the same fluence, FRB 20180916B is more active below 200 MHz than at 1.4 GHz. Combining our results with previous upper-limits on the all-sky FRB rate at 150 MHz, we find that there are 3-450 FRBs/sky/day above 50 Jy ms at 90% confidence. We are able to rule out the scenario in which companion winds cause FRB periodicity. We also demonstrate that some FRBs live in clean environments that do not absorb or scatter low-frequency radiation.Comment: 50 pages, 14 figures, 3 tables, submitte

Neurotransmitter and tryptophan metabolite concentration changes in the complete Freund's adjuvant model of orofacial pain.

The neurochemical background of the evolution of headache disorders, still remains partially undiscovered. Accordingly, our aim was to further explore the neurochemical profile of Complete Freund's adjuvant (CFA)-induced orofacial pain, involving finding the shift point regarding small molecule neurotransmitter concentrations changes vs. that of the previously characterized headache-related neuropeptides. The investigated neurotransmitters consisted of glutamate, γ-aminobutyric acid, noradrenalin and serotonin. Furthermore, in light of its influence on glutamatergic neurotransmission, we measured the level of kynurenic acid (KYNA) and its precursors in the kynurenine (KYN) pathway (KP) of tryptophan metabolism.The effect of CFA was evaluated in male Sprague Dawley rats. Animals were injected with CFA (1 mg/ml, 50 μl/animal) into the right whisker pad. We applied high-performance liquid chromatography to determine the concentrations of the above-mentioned compounds from the trigeminal nucleus caudalis (TNC) and somatosensory cortex (ssCX) of rats. Furthermore, we measured some of these metabolites from the cerebrospinal fluid and plasma as well. Afterwards, we carried out permutation t-tests as post hoc analysis for pairwise comparison.Our results demonstrated that 24 h after CFA treatment, the level of glutamate, KYNA and that of its precursor, KYN was still elevated in the TNC, all diminishing by 48 h. In the ssCX, significant concentration increases of KYNA and serotonin were found.This is the first study assessing neurotransmitter changes in the TNC and ssCX following CFA treatment, confirming the dominant role of glutamate in early pain processing and a compensatory elevation of KYNA with anti-glutamatergic properties. Furthermore, the current findings draw attention to the limited time interval where medications can target the glutamatergic pathways

Angular momentum regulates H i gas content and H i central hole size in the discs of spirals

International audienceThe neutral atomic hydrogen (H I) content of spiral galaxies has been observed to vary with environment, with more H I-deficient spirals residing in high-density environments. This can be attributed to environmental effects such as ram pressure stripping and tidal interactions, which remove H I from the discs of galaxies. However, some spirals in low-density environments have also been observed to have relatively low H I mass fractions. The low densities of the intergalactic medium and lack of nearby galaxies in such environments make ram pressure stripping and tidal interactions unlikely candidates of gas removal. What then could be making these spirals HI deficient? Obreschkow et al. introduced a parameter-free model for the neutral atomic gas fraction (f atm), in a symmetric equilibrium disc as a function of the global atomic stability parameter (q), which depends on specific angular momentum. In order to examine if this model accounts for H I-deficient galaxies in low-density environments, we have used the M H I −M R scaling relation to select six H I-deficient spiral galaxies and observed them with the Australia Telescope Compact Array. By measuring their f atm and q values we find that the galaxies owe their observed H I deficiencies to low specific angular momenta. Additionally, we also find that the central H I hole sizes of our sample galaxies are related to their q values, following the prediction of Obreschkow et al. This result brings to light the importance of angular momentum in understanding the physics of the interstellar medium in the discs of galaxies and consequently their evolution

Agysérült betegek tracheostomájának dekanülálása bronchoszkópos ellenőrzés mellett | Tracheostomy decannulation of patients with brain injury guided by flexible bronchoscope

Bevezetés: Az intenzív terápia területén bekövetkezett fejlődés a kritikus állapotú traumás és vascularis eredetű súlyos agysérült betegek életkilátásait jelentősen javította, és növelte a rehabilitációs osztályra kerülő tracheostomizált, kanülös betegek számát. Célkitűzés: A szerzők ismertetik a tracheakanül biztonságos eltávolításának általuk kidolgozott technikáját a súlyos agysérültek rehabilitációja során. Módszer: Prospektív leíró vizsgálat, amelyet az Országos Orvosi Rehabilitációs Intézet súlyos agysérültek rehabilitációjával foglalkozó osztályain folytattak. Eredmények: 2013. január 1. és december 31. között 20 betegnél 30 esetben végeztek bronchoszkópos tracheavizsgálatot dekanülálással kapcsolatosan. A betegeket különböző eredetű agykárosodás miatt kezelték a rehabilitációs osztályon: 6 esetben trauma, 5 esetben ischaemiás stroke, 3 betegnél agytörzsi vérzés, kettőnél kisagyi, egy betegnél bifrontalis vérzés volt az alapbetegség, míg 1-1 beteg esetében kóroki tényezőként meningeoma, pneumonia következtében fellépő többszervi elégtelenség és anoxiás agykárosodás szerepelt. A betegek átlagéletkora 44 év (18–80) volt. A vizsgálat során 13 esetben végeztek sikeres, szövődménymentes dekanülálást. A kanülök eltávolítása átlagosan 62 nap után történt. Következtetések: A biztonságos betegellátás érdekében, a szakterületek fejlődéséhez a különböző gyógyítóosztályoknak is alkalmazkodniuk kell. A súlyos agysérült betegek korai rehabilitációs kezelésének feltétele a tracheostomával érkező betegek biztonságos ellátása, majd lehetőség szerinti dekanülálása. Ehhez a tevékenységhez a szerzők szükségesnek tartják a bronchoszkópiában jártas szakember bevonását és helyi protokoll kialakítását. Orv. Hetil., 2014, 155(28), 1108–1112. | Introduction: Progress in intensive care management of patients with severe brain injury due to trauma or vascular lesion significantly improved the mortality and increased the number of patients with tracheostomy who undergo treatment in rehabilitation departments. Aim: The aim of the authors was to describe the safe tracheostomy decannulation method of patients with brain injury during rehabilitation. Method: A prospective, descriptive study performed at the rehabilitation departments of the National Institute for Medical Rehabilitation in Budapest, Hungary. Results: From January 1 until December 31, 2013, thirty examinations with flexible bronchoscope for tracheostomy decannulation were performed in 20 patients. The patients were admitted to the rehabilitation wards with various brain injuries: 6 patients suffered from trauma, 5 had ischemic stroke, 3 patients had brain stem haemorrhage, 2 patients cerebellar and one patient bifrontal haemorrhage. One patient had menangioma, and one had multiple organ failure and anoxic brain injury caused by pneumonia. The average age of patients was 44 years (range, 18–80 years). During the procedure successful decannulation was performed in 13 patients. Decannulation occurred 62 days after tracheostomy on average. Conclusions: Safe patient care requires that various medical departments keep pace with the development of different specialities. To ensure early rehabilitation of patients with severe brain injury having tracheostomy, safe treatment and, if possible, decannulation should be performed. This procedure requires the involvement of a physician with bronchoscopy skills as well as the development of local protocols. Orv. Hetil., 2014, 155(28), 1108–1112