ALMA observations of the young protostellar system Barnard 1b: signatures of an incipient hot corino in B1b-S.

The Barnard 1b core shows signatures of being at the earliest stages of low-mass star formation, with two extremely young and deeply embedded protostellar objects. Hence, this core is an ideal target to study the structure and chemistry of the first objects formed in the collapse of prestellar cores. We present ALMA Band 6 spectral line observations at ~0.6″ of angular resolution towards Barnard 1b. We have extracted the spectra towards both protostars, and used a Local Thermodynamic Equilibrium (LTE) model to reproduce the observed line profiles. B1b-S shows rich and complex spectra, with emission from high energy transitions of complex molecules, such as CH3OCOH and CH3CHO, including vibrational level transitions. We have tentatively detected for the first time in this source emission from NH2CN, NH2CHO, CH3CH2OH, CH2OHCHO, CH3CH2OCOH and both aGg' and gGg' conformers of (CH2OH)2. This is the first detection of ethyl formate (CH3CH2OCOH) towards a low-mass star forming region. On the other hand, the spectra of the FHSC candidate B1b-N are free of COMs emission. In order to fit the observed line profiles in B1b-S, we used a source model with two components: an inner hot and compact component (200 K, 0.35″) and an outer and colder one (60 K, 0.6″). The resulting COM abundances in B1b-S range from 10-13 for NH2CN and NH2CHO, up to 10-9 for CH3OCOH. Our ALMA Band 6 observations reveal the presence of a compact and hot component in B1b-S, with moderate abundances of complex organics. These results indicate that a hot corino is being formed in this very young Class 0 source.

Proposal of an integrative model of adjustment to chronic conditions: An understanding of the process of psychosocial adjustment to living with type 2 diabetes.

Psychosocial adjustment to living with a chronic condition was explored in this grounded theory study, focusing on type 2 diabetes. Despite a range of relevant theories, there is limited understanding of the process of adjustment. The study aimed to address this issue. That was achieved through collecting and analysing personal narratives using individual interviews and focus groups. This allowed for the development of a normative integrative model of adjustment to chronic conditions based on biopsychosocial principles. The integrative model of adjustment to chronic condition has the potential to lead to improved understanding of adjustment processes.

Chemical segregation in the young protostars Barnard 1b-N and S Evidence of pseudo-disk rotation in Barnard 1b-S.

The extremely young Class 0 object B1b-S and the first hydrostatic core (FSHC) candidate, B1b-N, provide a unique opportunity to study the chemical changes produced in the elusive transition from the prestellar core to the protostellar phase. We present 40"×70" images of Barnard 1b in the 13CO 1→0, C18O 1→0, NH2D 11,1a→10,1s, and SO 32→21 lines obtained with the NOEMA interferometer. The observed chemical segregation allows us to unveil the physical structure of this young protostellar system down to scales of ∼500 au. The two protostellar objects are embedded in an elongated condensation, with a velocity gradient of ∼0.2-0.4 m s-1 au-1 in the east-west direction, reminiscent of an axial collapse. The NH2D data reveal cold and dense pseudo-disks (R∼500-1000 au) around each protostar. Moreover, we observe evidence of pseudo-disk rotation around B1b-S. We do not see any signature of the bipolar outflows associated with B1b-N and B1b-S, which were previously detected in H2CO and CH3OH, in any of the imaged species. The non-detection of SO constrains the SO/CH3OH abundance ratio in the high-velocity gas.

Evidence for disks at an early stage in class 0 protostars?

AIMS: The formation epoch of protostellar disks is debated because of the competing roles of rotation, turbulence, and magnetic fields in the early stages of low-mass star formation. Magnetohydrodynamics simulations of collapsing cores predict that rotationally supported disks may form in strongly magnetized cores through ambipolar diffusion or misalignment between the rotation axis and the magnetic field orientation. Detailed studies of individual sources are needed to cross check the theoretical predictions. METHODS: We present 0.06 - 0.1 ″ resolution images at 350 GHz toward B1b-N and B1b-S, which are young class 0 protostars, possibly first hydrostatic cores. The images have been obtained with ALMA, and we compare these data with magnetohydrodynamics simulations of a collapsing turbulent and magnetized core. RESULTS: The submillimeter continuum emission is spatially resolved by ALMA. Compact structures with optically thick 350 GHz emission are detected toward both B1b-N and B1b-S, with 0.2 and 0.35″ radii (46 and 80 au at the Perseus distance of 230 pc), within a more extended envelope. The flux ratio between the compact structure and the envelope is lower in B1b-N than in B1b-S, in agreement with its earlier evolutionary status. The size and orientation of the compact structure are consistent with 0.2″ resolution 32 GHz observations obtained with the Very Large Array as a part of the VANDAM survey, suggesting that grains have grown through coagulation. The morphology, temperature, and densities of the compact structures are consistent with those of disks formed in numerical simulations of collapsing cores. Moreover, the properties of B1b-N are consistent with those of a very young protostar, possibly a first hydrostatic core. These observations provide support for the early formation of disks around low-mass protostars.

Analysis of the Herschel/HEXOS Spectral Survey Towards Orion South: A massive protostellar envelope with strong external irradiation.

We present results from a comprehensive submillimeter spectral survey toward the source Orion South, based on data obtained with the HIFI instrument aboard the Herschel Space Observatory, covering the frequency range 480 to 1900 GHz. We detect 685 spectral lines with S/N > 3σ, originating from 52 different molecular and atomic species. We model each of the detected species assuming conditions of Local Thermodynamic Equilibrium. This analysis provides an estimate of the physical conditions of Orion South (column density, temperature, source size, & V LSR ). We find evidence for three different cloud components: a cool (T ex ~ 20 - 40 K), spatially extended (> 60″), and quiescent (ΔVFWHM ~ 4 km s -1) component; a warmer (T ex ~ 80 - 100 K), less spatially extended (~ 30″), and dynamic (ΔVFWHM ~ 8 km s -1) component, which is likely affected by embedded outflows; and a kinematically distinct region (T ex > 100 K; V LSR ~ 8 km s -1), dominated by emission from species which trace ultraviolet irradiation, likely at the surface of the cloud. We find little evidence for the existence of a chemically distinct "hot core" component, likely due to the small filling factor of the hot core or hot cores within the Herschel beam. We find that the chemical composition of the gas in the cooler, quiescent component of Orion South more closely resembles that of the quiescent ridge in Orion-KL. The gas in the warmer, dynamic component, however, more closely resembles that of the Compact Ridge and Plateau regions of Orion-KL, suggesting that higher temperatures and shocks also have an influence on the overall chemistry of Orion South.

VELOCITY-RESOLVED [C ii] EMISSION AND [C ii]/FIR MAPPING ALONG ORION WITH HERSCHEL.

We present the first ~7.5'×11.5' velocity-resolved (~0.2 km s-1) map of the [C ii] 158 µm line toward the Orion molecular cloud 1 (OMC 1) taken with the Herschel/HIFI instrument. In combination with far-infrared (FIR) photometric images and velocity-resolved maps of the H41α hydrogen recombination and CO J=2-1 lines, this data set provides an unprecedented view of the intricate small-scale kinematics of the ionized/PDR/molecular gas interfaces and of the radiative feedback from massive stars. The main contribution to the [C ii] luminosity (~85 %) is from the extended, FUV-illuminated face of the cloud (G0>500, nH>5×103 cm-3) and from dense PDRs (G≳104, nH≳105 cm-3) at the interface between OMC 1 and the H ii region surrounding the Trapezium cluster. Around ~15 % of the [C ii] emission arises from a different gas component without CO counterpart. The [C ii] excitation, PDR gas turbulence, line opacity (from [13C ii]) and role of the geometry of the illuminating stars with respect to the cloud are investigated. We construct maps of the L[C ii]/LFIR and LFIR/MGas ratios and show that L[C ii]/LFIR decreases from the extended cloud component (~10-2-10-3) to the more opaque star-forming cores (~10-3-10-4). The lowest values are reminiscent of the "[C ii] deficit" seen in local ultra-luminous IR galaxies hosting vigorous star formation. Spatial correlation analysis shows that the decreasing L[C ii]/LFIR ratio correlates better with the column density of dust through the molecular cloud than with LFIR/MGas. We conclude that the [C ii] emitting column relative to the total dust column along each line of sight is responsible for the observed L[C ii]/LFIR variations through the cloud.

74 MHz nonthermal emission from molecular clouds: evidence for a cosmic ray dominated region at the galactic center.

We present 74 MHz radio continuum observations of the Galactic center region. These measurements show nonthermal radio emission arising from molecular clouds that is unaffected by free­free absorption along the line of sight. We focus on one cloud, G0.13-0.13, representative of the population of molecular clouds that are spatially correlated with steep spectrum (α(327MHz)(74MHz) = 1.3 ± 0.3) nonthermal emission from the Galactic center region. This cloud lies adjacent to the nonthermal radio filaments of the Arc near l 0.2° and is a strong source of 74 MHz continuum, SiO (2-1), and Fe I Kα 6.4 keV line emission. This three-way correlation provides the most compelling evidence yet that relativistic electrons, here traced by 74 MHz emission, are physically associated with the G0.13-0.13 molecular cloud and that low-energy cosmic ray electrons are responsible for the Fe I Kα line emission. The high cosmic ray ionization rate 10(­1)3 s(­1) H(­1) is responsible for heating the molecular gas to high temperatures and allows the disturbed gas to maintain a high-velocity dispersion. Large velocity gradient (LVG) modeling of multitransition SiO observations of this cloud implies H2 densities 10(4­5) cm(­3) and high temperatures. The lower limit to the temperature of G0.13-0.13 is 100 K, whereas the upper limit is as high as 1000 K. Lastly, we used a time-dependent chemical model in which cosmic rays drive the chemistry of the gas to investigate for molecular line diagnostics of cosmic ray heating. When the cloud reaches chemical equilibrium, the abundance ratios of HCN/HNC and N2H+/HCO+ are consistent with measured values. In addition, significant abundance of SiO is predicted in the cosmic ray dominated region of the Galactic center. We discuss different possibilities to account for the origin of widespread SiO emission detected from Galactic center molecular clouds.

Hydride spectroscopy of the diffuse interstellar medium: new clues on the gas fraction in molecular form and cosmic ray ionization rate in relation to H3+.

The Herschel-guaranteed time key programme PRobing InterStellar Molecules with Absorption line Studies (PRISMAS)(1) is providing a survey of the interstellar hydrides containing the elements C, O, N, F and Cl. As the building blocks of interstellar molecules, hydrides provide key information on their formation pathways. They can also be used as tracers of important physical and chemical properties of the interstellar gas that are difficult to measure otherwise. This paper presents an analysis of two sight-lines investigated by the PRISMAS project, towards the star-forming regions W49N and W51. By combining the information extracted from the detected spectral lines, we present an analysis of the physical properties of the diffuse interstellar gas, including the electron abundance, the fraction of gas in molecular form, and constraints on the cosmic ray ionization rate and the gas density.

Density functional theory-based simulations of sum frequency generation spectra involving methyl stretching vibrations: effect of the molecular model on the deduced molecular orientation and comparison with an analytical approach.

The knowledge of the first hyperpolarizability tensor elements of molecular groups is crucial for a quantitative interpretation of the sum frequency generation (SFG) activity of thin organic films at interfaces. Here, the SFG response of the terminal methyl group of a dodecanethiol (DDT) monolayer has been interpreted on the basis of calculations performed at the density functional theory (DFT) level of approximation. In particular, DFT calculations have been carried out on three classes of models for the aliphatic chains. The first class of models consists of aliphatic chains, containing from 3 to 12 carbon atoms, in which only one methyl group can freely vibrate, while the rest of the chain is frozen by a strong overweight of its C and H atoms. This enables us to localize the probed vibrational modes on the methyl group. In the second class, only one methyl group is frozen, while the entire remaining chain is allowed to vibrate. This enables us to analyse the influence of the aliphatic chain on the methyl stretching vibrations. Finally, the dodecanethiol (DDT) molecule is considered, for which the effects of two dielectrics, i.e. n-hexane and n-dodecane, are investigated. Moreover, DDT calculations are also carried out by using different exchange-correlation (XC) functionals in order to assess the DFT approximations. Using the DFT IR vectors and Raman tensors, the SFG spectrum of DDT has been simulated and the orientation of the methyl group has then been deduced and compared with that obtained using an analytical approach based on a bond additivity model. This analysis shows that when using DFT molecular properties, the predicted orientation of the terminal methyl group tends to converge as a function of the alkyl chain length and that the effects of the chain as well as of the dielectric environment are small. Instead, a more significant difference is observed when comparing the DFT-based results with those obtained from the analytical approach, thus indicating the importance of a quantum chemical description of the hyperpolarizability tensor elements of the methyl group.

Myelin water imaging in multiple sclerosis: quantitative correlations with histopathology.

Various magnetic resonance (MR) techniques are used to study the pathological evolution of demyelinating diseases, such as multiple sclerosis (MS). However, few studies have validated MR derived measurements with histopathology. Here, we determine the correlation of myelin water imaging, an MR measure of myelin content, with quantitative histopathologic measures of myelin density. The multi-component T2 distribution of water was determined from 25 formalin-fixed MS brain samples using a multi-echo T2 relaxation MR experiment. The myelin water fraction (MWF), defined as T2 signal below 30 milliseconds divided by the total signal, was determined for various regions of interest and compared to Luxol fast blue (myelin stain) mean optical density (OD) for each sample. MWF had a strong correlation with myelin stain [mean (range) R2 = 0.67 (0.45-0.92)], validating MWF as a measure of myelin density. This quantitative technique has many practical applications for the in vivo monitoring of demyelination and remyelination in a variety of disorders of myelin.

Outgassing behavior and composition of comet C/1999 S4 (LINEAR) during its disruption.

The gas activity of comet C/1999 S4 (LINEAR) was monitored at radio wavelengths during its disruption. A runaway fragmentation of the nucleus may have begun around 18 July 2000 and proceeded until 23 July. The mass in small icy debris (

[Effect of lipid lowering diet on serum lipids in peritoneal dialysis patients]. / Wplyw diety hipolipemizujacej na profil lipidowy surowicy chorych ze schylkowa niewydolnoscia nerek leczonych dializa otrzewnowa.

The aim of the study was to assess an effect of lipid lowering diet on serum lipids in peritoneal dialysis patients. Total cholesterol (TC) decreased after 3 months of low-fat diet from 203.7 mg/dl to 181 mg/dl, probably due to increased P/S ratio (PUFA/SFA) from 0.4 to 0.57. After another 3 months of the diet, a decrease in P/S ratio and concomitant increase in TC and LDL-C levels were found. Nutritional status of patients during lipid lowering diet was stable.

Submillimeter fourier-transform spectrometer measurements of atmospheric opacity above mauna kea.

We present accurately calibrated submillimeter atmospheric transmission spectra obtained with a Fourier-transform spectrometer at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. These measurements cover the 0.9-0.3-mm wavelength range and are the first in a series aimed at defining the terrestrial long-wave atmospheric transmission curve. The 4.1-km altitude of the Mauna Kea site provides access to extremely low zenith water-vapor columns, permitting atmospheric observations at frequencies well above those possible from sea level. We describe the calibration procedures, present our first well-calibrated transmission spectra, and compare our results with those of a single-layer atmospheric transmission model, AT. With an empirical best-fit continuum opacity term included, this simple single-layer model provides a remarkably good fit to the opacity data for H(2)O line profiles described by either van Vleck-Weisskopf or kinetic shapes.

[The prevalence of bacterial and fungal aerosol in homes, offices and ambient air of Upper Silesia. Preliminary results]. / Wystepowanie aerozolu bakteryjnego i grzybowego w mieszkaniach, biurach i srodowisku zewnetrznym Górnego Slaska. Wyniki Wstepne.

Quantitative criteria of microbiological air quality in homes and offices are needed for practical reasons. The purpose of this study was to obtain the preliminary characteristic of bacterial and fungal aerosols in healthy buildings. It was analysed the concentrations levels and size distributions of the investigated bioaerosols. The obtained data can be treated as a first step in the direction of determining so called normal level for different bioaerosols in homes and offices in Poland. The concentrations of airborne bacteria and fungi were measured using 6-stage Andersen impactor. The Trypcase Soy Agar were applied for bacteria and 2% Malt Extract Agar for fungi. The bacteria samples were incubated for 2 days at 37 degrees C and the fungi samples respectively for 4 days at 25 degrees C. The indoor levels of bacterial aerosol (homes: 212-888 cfu/m3, offices: 136-542 cfu/m3) were higher than the outdoor levels (respectively: 42-386 cfu/m3 and 13-115 cfu/m3). The fungal aerosol concentrations were lower indoors (homes: 81-383 cfu/m3, offices: 18-133 cfu/m3) than outdoors (94-625 cfu/m3). There were distinctly higher concentrations of the investigated bioaerosols in homes than in offices. The aerodynamic diameter of most bacterial particles were higher than 7 microns, both in indoor air (homes: 57-260 cfu/m3, offices 19-118 cfu/m3) and outdoor air (respectively: 9-145 cfu/m3 and 0-71 cfu/m3). The maximum for fungal spore levels were observed in the size range 3.3-4.7 and 2.1-3.3 microns in the instance of homes (respectively: 12-155 cfu/m3 and 19-154 cfu/m3) and in the size range 2.1-3.3 microns in the instance of offices (6-55 cfu/m3). Largest numbers of this bioaerosol in outdoor air were isolated in the size range 2.1-3.3 microns (25-208 cfu/m3). Although there are some proposals for an upper limit of the normal indoor concentration of airborne bacteria and fungi, but due to different climate and housing conditions we can expect other normal range of fungal and bacterial aerosol in Polish homes.

Spectroscopic evidence for interstellar ices in comet Hyakutake.

Volatile compounds in comets are the most pristine materials surviving from the time of formation of the Solar System, and thus potentially provide information about conditions that prevailed in the primitive solar nebula. Moreover, comets may have supplied a substantial fraction of the volatiles on the terrestrial planets, perhaps including organic compounds that played a role in the origin of life on Earth. Here we report the detection of hydrogen isocyanide (HNC) in comet Hyakutake. The abundance of HNC relative to hydrogen cyanide (HCN) is very similar to that observed in quiescent interstellar molecular clouds, and quite different from the equilibrium ratio expected in the outermost solar nebula, where comets are thought to form. Such a departure from equilibrium has long been considered a hallmark of gas-phase chemical processing in the interstellar medium, suggesting that interstellar gases have been incorporated into the comet's nucleus, perhaps as ices frozen onto interstellar grains. If this interpretation is correct, our results should provide constraints on the temperature of the solar nebula, and the subsequent chemical processes that occurred in the region where comets formed.

Characterization of a submillimeter high-angular-resolution camera with a monolithic silicon bolometer array for the Caltech Submillimeter Observatory.

We constructed a 24-pixel bolometer camera operating in the 350- and 450-µm atmospheric windows for the Caltech Submillimeter Observatory (CSO). This instrument uses a monolithic silicon bolometer array that is cooled to approximately 300 mK by a single-shot (3)He refrigerator. First-stage amplification is provided by field-effect transistors at approximately 130 K. The sky is imaged onto the bolometer array by means of several mirrors outside the Dewar and a cold off-axis elliptical mirror inside the cryostat. The beam is defined by cold aperture and field stops, which eliminates the need for any condensing horns. We describe the instrument, present measurements of the physical properties of the bolometer array, describe the performance of the electronics and the data-acquisition system, and demonstrate the sensitivity of the instrument operating at the observatory. Approximate detector noise at 350 µm is 5 × 10(-15) W/√Hz, referenced to the entrance of the Dewar, and the CSO system noise-equivalent flux density is approximately 4 Jy/√Hz. These values are within a factor of 2.5 of the background limit.

The effect of serum growth factors and xyloside on molecular aging of proteoglycan in embryonal chick cartilage.

The effects of normal human serum, insulin-like growth factor and beta-D-xyloside on the synthesis of proteoglycan, as well as their differential effect on the synthesis of chondroitin sulfate and keratan sulfate side-chains, were studied in chick embryonal cartilage. The glycosaminoglycans found in the incubation medium were mainly intact carbohydrate moieties of partially degraded proteoglycan molecules, whereas the tissue-bound glycosaminoglycans were of intact proteoglycan molecules. In incubations with normal human serum, the synthesis of the chondroitin sulfate side-chains of the tissue-bound glycosaminoglycans was preferentially stimulated, while the percentage of medium glycosaminoglycan (out of the total glycosaminoglycan in tissue and medium) was reduced, compared to control incubations. In incubations with insulin-like growth factor, the synthesis of the keratan sulfate side-chains of the tissue-bound glycosaminoglycan was preferentially stimulated, whereas the percentage of the medium glycosaminoglycan resembled that of control incubations. In incubations with xyloside, a marked reduction of tissue-bound glycosaminoglycan was noticed, mainly of chondroitin sulfate chains, and only a slight decrease in keratan sulfate chains. Human serum of various age groups stimulated proteoglycan synthesis in embryonal chick cartilage to almost the same extent. However, sera from babies and adults were found to stimulate chondroitin sulfate chains preferentially, whereas serum of aged subjects preferentially enhanced the synthesis of keratan sulfate chains. These findings suggest that the synthesis and/or degradation of the various types of glycosaminoglycan chains (chondroitin sulfate and keratan sulfate) of cartilage proteoglycan can be regulated differentially by serum growth factors. Secondly, the growth hormone-mediated serum factor (insulin-like growth factor) seems to play a role in molecular aging of proteoglycans.