Differential cortical monoamines release during exercise in rats chronically implanted with microdialysis probes

Physical exercise is known to positively influence mood, to reduce anxiety and to improve reaction to stress. Cerebral monoaminergic systems are thought to underly the neurochemical influence of exercise on mood and behavior. We hypothesized that beneficial effects of exercise can be shown by variations of neurotransmitters release in the cerebral cortex. We aimed at demonstrating that there is a temporal relationship between release of plasma and cerebral monoamines (A, NA, 5-HT, DA) and spontaneous running exercise in rats. Ten Spague Dawley rats (250 g) were chronically implanted (for up to 39 days) with a left common carotid cannula and a bilateral fronto-parietal transverse microdialysis probe. Blood and microdialysate were sampled 7 and 15 days after surgery. Sampling occurred for a total 180 minutes (divided in 20 minutes samples) during a one hour each period: Rest, treadmill exercise (80%VO2max), and post-exercise rest. One animal was used for in vivo microdialysis recovery study. Seven animals were used for monoamines studies. Results showed: (1) that the development of the rat head device allowed sampling in an unrestrained running rat; (2) the permeability and functionality of carotid cannulas and microdialysis probes for up to 39 days in chronic implantation; (3) NA release increase at the end of exercise (100-120 min) and during the post-exercise rest period (120 to 180 min); (4) a significant DOPAC increase of 36% during exercise and of 58.3% during post-exercise rest when compared to rest. Post-exercise DOPAC increase was of 15.5% when compared to exercise; (5) that 5-HIAA did not vary at any time point. These findings indicate that spontaneous exercise specific stress induces DOPAC extracellular increase resulting from DA neuronal terminal release in layers IV and V of the fronto-parietal terminal field cortex. Differences between DA, NA, 5-HT release might be due to synaptic arrangements or to differences in the actual release of NT and in neural paths evoked during acute exercise

Discovery of Water Vapor in the High-redshift Quasar APM 08279+5255 at z = 3.91

We report a detection of the excited 2_(20)-2_(11) rotational transition of para-H_2O in APM 08279+5255 using the IRAM Plateau de Bure Interferometer. At z = 3.91, this is the highest-redshift detection of interstellar water to date. From large velocity gradient modeling, we conclude that this transition is predominantly radiatively pumped and on its own does not provide a good estimate of the water abundance. However, additional water transitions are predicted to be detectable in this source, which would lead to an improved excitation model. We also present a sensitive upper limit for the hydrogen fluoride (HF) J = 1-0 absorption toward APM 08279+5255. While the face-on geometry of this source is not favorable for absorption studies, the lack of HF absorption is still puzzling and may be indicative of a lower fluorine abundance at z = 3.91 compared with the Galactic interstellar medium

High-velocity hot CO emission close to Sgr A*: Herschel/HIFI submillimeter spectral survey toward Sgr A*

The properties of molecular gas, the fuel that forms stars, inside the cavity of the circumnuclear disk (CND) are not well constrained. We present results of a velocity-resolved submillimeter scan (~480 to 1250 GHz}) and [CII]158um line observations carried out with Herschel/HIFI toward Sgr A*; these results are complemented by a ~2'x2' CO (J=3-2) map taken with the IRAM 30 m telescope at ~7'' resolution. We report the presence of high positive-velocity emission (up to about +300 km/s) detected in the wings of CO J=5-4 to 10-9 lines. This wing component is also seen in H2O (1_{1,0}-1_{0,1}) a tracer of hot molecular gas; in [CII]158um, an unambiguous tracer of UV radiation; but not in [CI]492,806 GHz. This first measurement of the high-velocity CO rotational ladder toward Sgr A* adds more evidence that hot molecular gas exists inside the cavity of the CND, relatively close to the supermassive black hole (< 1 pc). Observed by ALMA, this velocity range appears as a collection of CO (J=3-2) cloudlets lying in a very harsh environment that is pervaded by intense UV radiation fields, shocks, and affected by strong gravitational shears. We constrain the physical conditions of the high positive-velocity CO gas component by comparing with non-LTE excitation and radiative transfer models. We infer T_k~400 K to 2000 K for n_H~(0.2-1.0)x10^5 cm^-3. These results point toward the important role of stellar UV radiation, but we show that radiative heating alone cannot explain the excitation of this ~10-60 M_Sun component of hot molecular gas inside the central cavity. Instead, strongly irradiated shocks are promising candidates.Comment: Accepted for publication in A&A Letters ( this v2 includes corrections by language editor

Dense molecular globulettes and the dust arc towards the runaway O star AE Aur (HD 34078)

Some runaway stars are known to display IR arc-like structures around them, resulting from their interaction with surrounding interstellar material. The properties of these features as well as the processes involved in their formation are still poorly understood. We aim at understanding the physical mechanisms that shapes the dust arc observed near the runaway O star AEAur (HD34078). We obtained and analyzed a high spatial resolution map of the CO(1-0) emission that is centered on HD34078, and that combines data from both the IRAM interferometer and 30m single-dish antenna. The line of sight towards HD34078 intersects the outer part of one of the detected globulettes, which accounts for both the properties of diffuse UV light observed in the field and the numerous molecular absorption lines detected in HD34078's spectra, including those from highly excited H2 . Their modeled distance from the star is compatible with the fact that they lie on the 3D paraboloid which fits the arc detected in the 24 {\mu}m Spitzer image. Four other compact CO globulettes are detected in the mapped area. These globulettes have a high density and linewidth, and are strongly pressure-confined or transient. The good spatial correlation between the CO globulettes and the IR arc suggests that they result from the interaction of the radiation and wind emitted by HD 34078 with the ambient gas. However, the details of this interaction remain unclear. A wind mass loss rate significantly larger than the value inferred from UV lines is favored by the large IR arc size, but does not easily explain the low velocity of the CO globulettes. The effect of radiation pressure on dust grains also meets several issues in explaining the observations. Further observational and theoretical work is needed to fully elucidate the processes shaping the gas and dust in bow shocks around runaway O stars. (Abridged)Comment: Accepted for publication in Astronomy & Astrophysic

Interstellar CH absorption in the diffuse interstellar medium along the sight-lines to G10.6–0.4 (W31C), W49N, and W51

We report the detection of the ground state N, J = 1, 3/2 → 1, 1/2 doublet of the methylidyne radical CH at ~532 GHz and ~536 GHz with the Herschel/HIFI instrument along the sight-line to the massive star-forming regions G10.6–0.4 (W31C), W49N, and W51. While the molecular cores associated with these massive star-forming regions show emission lines, clouds in the diffuse interstellar medium are detected in absorption against the strong submillimeter background. The combination of hyperfine structure with emission and absorption results in complex profiles, with overlap of the different hyperfine components. The opacities of most of the CH absorption features are linearly correlated with those of CCH, CN, and HCO^+ in the same velocity intervals. In specific narrow velocity intervals, the opacities of CN and HCO^+ deviate from the mean trends, giving rise to more opaque absorption features. We propose that CCH can be used as another tracer of the molecular gas in the absence of better tracers, with [CCH]/[H_2] ~3.2 ± 1.1 × 10^(−8). The observed [CN]/[CH], [CCH]/[CH] abundance ratios suggest that the bulk of the diffuse matter along the lines of sight has gas densities n_H = n(H) + 2n(H_2) ranging between 100 and 1000 cm^(−3)

Monte-Carlo Simulation of &Gamma;-ray and Fast Neutron Radiolysis of Liquid Water and 0.4 M H2SO4 Solutions at Temperatures Up to 325oC

Monte-Carlo simulations were used to study the radiolysis of liquid water at 25-325oC when subjected to low linear energy transfer (LET) of 60Co γ-ray radiation and fast neutrons of 2 and 0.8 MeV. The energy deposited in the early stage of 60Co γ-ray irradiation was approximated by considering short segments (~150 μm) of 300 MeV proton tracks, corresponding to an average LET of ~0.3 keV/μm. In case of 2 MeV fast neutrons, the energy deposited was considered by using short segments (~5 μm) of energy at 1.264, 0.465, 0.171, 0.063 and 0.24 MeV. 0.8 MeV fast neutrons were approximated by 0.505, 0.186, 0.069 and 0.025 MeV protons. The effect of 0.4 M H2SO4 solution on radiolysis was also studied by this method for both 60Co γ-rays and 0.8 MeV fast neutrons. The simulated results at the time of 10-7s after irradiation were obtained and compared with the available experimental results published by other researchers to be in excellent agreement with them over the entire temperature ranges and radiation sources studied. Except for g(H2) that increase with temperature rises, the general behaviors of higher radical products and lower molecular products at higher temperatures were obtained. The LET effect is also validated by this study, showing that the increase in LET would yield higher molecular and lower radical products. Studies on 0.4 M H2SO4 solutions also show good agreement between the computed and experimental data for γ-ray irrradiation: the presence of 0.4 M H+, except for g(H2) that gives lower value at 25oC and higher value at 325oC, gives the higher values for radicals and g(H2O2) at 25oC and lower values at 325oC, compared with that for neutral water. The computed data show good agreement with the experimental data for 0.4 M H2SO4 solutions induced by 0.8 MeV fast neutrons, except for g(H2) and g(H●) that gives good agreement up to 50oC, then the opposite tendencies with the further temperature rises. However, the simulated fast neutron radiolysis on acidic demonstrates similar tendencies on temperature dependence with that for simulated 60Co γ-radiolysis, but in different magnitude. For better understanding, more experimental data for fast neutrons are needed, especially under the acidic conditions. Received: 20 November 2009; Revised: 06 April 2011; Accepted: 12 April 201

Can alternative medical methods evoke neuro-functional somatosensory responses? A case study suggesting functional improvement

Somatosensory pathways act as the avenue in transferring information concerning the body and its interaction with the external environment to the brain. We aim to demonstrate that through studying somatosensory, motor cortical and subcortical networks, we can explain functional recovery after stimulations applied as an alternative medical treatment. Those stimulations might have evidenced neural pathways and networks important in recovery of function. Materials and methods: The de-identified medical reports of nine patients with initial presentations of cerebral trauma or stroke inducing paralysis were studied.These included the alternative treatments they received and other available materials such as videos and photographs. Patients were either males or females and their ages ranged from 20 to 95-year old. All patients, were first treated through conventional medical interventions, including physical therapy. Patients consulted for alternative medical treatment, one year or more, after the initial diagnosis. The alternative medical treatment consisted in multiple points stimulations. Twelve points of stimulation on the skull were used. Additional 4 points of stimulation were located at the right and left calves and at the right and left forearms. All stimulations had nociceptive and proprioceptive components. The stimulations were applied successively one by one (legs, arms, skull). The treatment consisted in a one-time (exceptionally two) session. The duration of each stimulation was about 0.5 s. Results show that in all 9 cases, patients had improvement in their motor skills, including gain of weight support and unassisted small walks, independent and voluntary movements of limbs. Improvement was steady over a period of one to several years. We believe that whether lesions included prefrontal cortical areas, or motor and sensory areas, the alternative treatment triggered existing or new neuronal networks as well as synaptic efficiency or reactivation, through highly increased, sensory nociceptive coupled to proprioceptive, afferences. Those results highlight the need to further investigate neural function of cortical and subcortical areas through non-invasive and indirect pathways stimulations, during a stable chronic phase after a CNS insult

A Constant Bar Fraction out to Redshift z~1 in the Advanced Camera for Surveys Field of the Tadpole Galaxy

Bar-like structures were investigated in a sample of 186 disk galaxies larger than 0.5 arcsec that are in the I-band image of the Tadpole galaxy taken with the HST ACS. We found 22 clear cases of barred galaxies, 21 galaxies with small bars that appear primarily as isophotal twists in a contour plot, and 11 cases of peculiar bars in clump-cluster galaxies, which are face-on versions of chain galaxies. The latter bars are probably young, as the galaxies contain only weak interclump emission. Four of the clearly barred galaxies at z~0.8-1.2 have grand design spirals. The bar fraction was determined as a function of galaxy inclination and compared with the analogous distribution in the local Universe. The bar fraction was also determined as a function of galaxy angular size. These distributions suggest that inclination and resolution effects obscure nearly half of the bars in our sample. The bar fraction was also determined as a function of redshift. We found a nearly constant bar fraction of 0.23+-0.03 from z~0 to z=1.1. When corrected for inclination and size effects, this fraction is comparable to the bar fraction in the local Universe, ~0.4, as tabulated for all bar and Hubble types in the Third Reference Catalogue of Galaxies. The average major axis of a barred galaxy in our sample is ~10 kpc after correcting for redshift with a LambdaCDM cosmology. Galaxy bars were present in normal abundance at least ~8 Gy ago (z~1); bar dissolution cannot be common during a Hubble time unless the bar formation rate is comparable to the dissolution rate.Comment: to appear in ApJ, Sept 1, 2004, Vol 612, 18 pg, 12 figure