1,439 research outputs found
X-ray emission from star-forming galaxies - I. High-mass X-ray binaries
Based on a homogeneous set of X-ray, infrared and ultraviolet observations
from Chandra, Spitzer, GALEX and 2MASS archives, we study populations of
high-mass X-ray binaries (HMXBs) in a sample of 29 nearby star-forming galaxies
and their relation with the star formation rate (SFR). In agreement with
previous results, we find that HMXBs are a good tracer of the recent star
formation activity in the host galaxy and their collective luminosity and
number scale with the SFR, in particular, Lx~2.6 10^{39} SFR. However, the
scaling relations still bear a rather large dispersion of ~0.4 dex, which we
believe is of a physical origin. We present the catalog of 1057 X-ray sources
detected within the ellipse for galaxies of our sample and construct the
average X-ray luminosity function (XLF) of HMXBs with substantially improved
statistical accuracy and better control of systematic effects than achieved in
previous studies. The XLF follows a power law with slope of 1.6 in the
logLx~35-40 luminosity range with a moderately significant evidence for a break
or cut-off at Lx~10^{40} erg/s. As before, we did not find any features at the
Eddington limit for a neutron star or a stellar mass black hole. We discuss
implications of our results for the theory of binary evolution. In particular
we estimate the fraction of compact objects that once upon their lifetime
experienced an X-ray active phase powered by accretion from a high mass
companion and obtain a rather large number, fx~0.2 (0.1 Myr/tau_x) (tau_x is
the life time of the X-ray active phase). This is ~4 orders of magnitude more
frequent than in LMXBs. We also derive constrains on the mass distribution of
the secondary star in HMXBs.Comment: 23 pages, 14 figures, 5 tables, MNRAS - Accepted 2011 September 2
A Faddeev Calculation for Pentaquark in Diquark Picture with Nambu-Jona-Lasinio Type Interaction
A Bethe-Salpeter-Faddeev (BSF) calculation is performed for the pentaquark
in the diquark picture of Jaffe and Wilczek in which is a
diquark-diquark- three-body system.
Nambu-Jona-Lasinio (NJL) model is used to calculate the lowest order diagrams
in the two-body scatterings of and . With the use of coupling
constants determined from the meson sector, we find that
interaction is attractive while interaction is repulsive, and there is no
bound pentaquark state. A bound pentaquark can only be
obtained with unphysically strong vector mesonic coupling constants.Comment: 4 pages, 4 figure
JOINT USE PARTNERSHIPS: EVALUATING THE FEASIBILITY OF A JOINT USE PARTNERHSIP BETWEEN THE CITY OF SAN LUIS OBISPO AND CAL POLY SAN LUIS OBISPO
As demand for additional athletic fields continues to increase, the City of San Luis Obispo is struggling to meet the recreation needs of the community. This project evaluated the feasibility of a joint use partnerships with Cal Poly San Luis Obispo for the shared use of the University’s underutilized Sports Complex, and made recommendations of strategies to address the City’s recreation needs. This project reviewed current and professional academic literature on successful approaches to joint use partnerships; conducted case study analyses on two Cal Poly facilities; and worked with City and University officials to examine the issues associated with establishing joint use agreements between state universities and local municipalities. Because little research currently exists to inform joint use partnerships between these two entities, the opportunities for exploration are many. Of particular interest are the fields of local and state policy and financing methods
Awake one stage bilateral thoracoscopic sympathectomy for palmar hyperhidrosis: a safe outpatient procedure
OBJECTIVE:
To verify the feasibility and compare the results of thoracoscopic sympathectomy under local anaesthesia (LA) and spontaneous breathing vs. general anaesthesia (GA) with one-lung ventilation.
METHODS:
Two groups of consecutive patients underwent one stage bilateral T2-T3 thoracoscopic sympathectomy under LA (n=15) and GA (n=30) by the same surgical team for treatment of primary palmar hyperhidrosis. The groups were homogeneous for relevant demographic, physiological and clinical data, including pulmonary function. In both groups, patient's satisfaction was evaluated 24h after surgery by a simple interview and scored into five grades (1=very poor to 5=excellent), while quality of life (QOL) was evaluated by SF-36 and Nottingham's Health Profile questionnaires before and 6 months after surgery. A cost comparison between groups concerning devices, drugs, global in operating room time, medical personnel and hospital stay was also carried out.
RESULTS:
No operative mortality was recorded. The overall in operating room time for the whole bilateral procedure under LA was 63.55+/-10.58 vs. 86.05+/-5.75 under GA (P<0.01) and temperature increased in all patients from a baseline of 25.42+/-0.56 up to 32.15+/-0.84 degrees C. All patients undergone LA were discharged the same day after a chest roentgenogram and a short stay in the outpatient clinic. Among them three patients (20%) experienced a minimal (<30%) pneumothorax that required no treatment, while five (33.3%) had a trunk compensatory sweating that spontaneously resolved on the long run. Patients undergoing GA were discharged after a mean stay of 1.38+/-0.6 days. Among these, eight (26.6%) had prolonged trunk compensatory sweating that did not persist longer than 3 months. At a follow-up of 7.16+/-2.97 months, QOL was significantly improved with no difference between groups. The overall rate of satisfaction was greater in the LA group (P<0.05).
CONCLUSIONS:
In our study, awake one stage bilateral thoracoscopic sympathectomy for palmar hyperhidrosis could be safely and effectively performed as an outpatient procedure in patients refusing GA. Postoperative quality of life was equal to that in patients undergone the same procedure under GA, while patient satisfaction was better and cost were significantly reduced
Quality of life after tailored combined surgery for stage I non-small-cell lung cancer and severe emphysema
Background. We analyzed the early and long-term quality of life changes occurring in 16 patients undergoing tailored combined surgery for stage I non-small-cell lung cancer (NSCLC) and severe emphysema. Methods. Mean age was 65 +/- 5 years. All patients had severe emphysema with severely impaired respiratory function and quality of life. Tumor resection was performed with sole lung volume reduction (LVR) in 5 patients, separate wedge resection in 3 patients, segmentectomy in 2 patients, and lobectomy in 6 patients. A bilateral LVR was performed in 5 patients. Quality of life was assessed at baseline and every 6 months postoperatively by the Short-form 36 (SF-36) item questionnaire. Results. Mean follow-up was 44 +/- 21 months. All tumors were pathologic stage I. There was no hospital mortality nor major morbidity. Significant improvements occurred for up to 36 months in the general health (p = 0.02) domain and for up to 24 months in physical functioning (p = 0.02), role physical (p = 0.005), and general health (P = 0.01) SF-36 domains. Associated improvements regarded dyspnea index (-1.3 +/- 0.6) forced expiratory volume in one second (+0.28 +/- 0.2L), residual volume (-1.18 +/- 0.5L) and 6-minute-walking test distance (+86 +/- 67 m). Actuarial 5-year survival was similar to that of patients with no cancer undergoing LVRS during the same period (68% vs 82%, p = not significant). Conclusions. Our study suggests that selected patients with stage I NSCLC and severe emphysema may significantly benefit from tailored combined surgery in terms of long-term quality of life and survival. (Ann Thorac Surg 2003;76:1821-7
Rapidly quantifying the relative distention of a human bladder
A device and method was developed to rapidly quantify the relative distention of the bladder of a human subject. An ultrasonic transducer is positioned on the human subject near the bladder. A microprocessor controlled pulser excites the transducer by sending an acoustic wave into the human subject. This wave interacts with the bladder walls and is reflected back to the ultrasonic transducer where it is received, amplified, and processed by the receiver. The resulting signal is digitized by an analog to digital converter, controlled by the microprocessor again, and is stored in data memory. The software in the microprocessor determines the relative distention of the bladder as a function of the propagated ultrasonic energy. Based on programmed scientific measurements and the human subject's past history as contained in program memory, the microprocessor sends out a signal to turn on any or all of the available alarms. The alarm system includes and audible alarm, the visible alarm, the tactile alarm, and the remote wireless alarm
Rapidly quantifying the relative distention of a human bladder
A device and method of rapidly quantifying the relative distention of the bladder in a human subject are disclosed. The ultrasonic transducer which is positioned on the subject in proximity to the bladder is excited by a pulser under the command of a microprocessor to launch an acoustic wave into the patient. This wave interacts with the bladder walls and is reflected back to the ultrasonic transducer, when it is received, amplified and processed by the receiver. The resulting signal is digitized by an analog-to-digital converter under the command of the microprocessor and is stored in the data memory. The software in the microprocessor determines the relative distention of the bladder as a function of the propagated ultrasonic energy; and based on programmed scientific measurements and individual, anatomical, and behavioral characterists of the specific subject as contained in the program memory, sends out a signal to turn on any or all of the audible alarm, the visible alarm, the tactile alarm, and the remote wireless alarm
X-ray emission from star-forming galaxies - II. Hot interstellar medium
We study the emission from the hot interstellar medium in a sample of nearby
late type galaxies defined in Paper I. Our sample covers a broad range of star
formation rates, from ~0.1 Msun/yr to ~17 Msun/yr and stellar masses, from
~3x10^8 Msun to ~6x10^10 Msun. We take special care of systematic effects and
contamination from bright and faint compact sources. We find that in all
galaxies at least one optically thin thermal emission component is present in
the unresolved emission, with the average temperature of = 0.24 keV. In
about ~1/3 of galaxies, a second, higher temperature component is required,
with the = 0.71 keV. Although statistically significant variations in
temperature between galaxies are present, we did not find any meaningful trends
with the stellar mass or star formation rate of the host galaxy. The apparent
luminosity of the diffuse emission in the 0.5-2 keV band linearly correlates
with the star formation rate with the scale factor of Lx/SFR\approx 8.3x10^38
erg/s per Msun/yr, of which in average ~30-40% is likely produced by faint
compact sources of various types. We attempt to estimate the bolometric
luminosity of the gas and and obtained results differing by an order of
magnitude, log(Lbol/SFR)\sim39-40, depending on whether intrinsic absorption in
star-forming galaxies was allowed or not. Our theoretically most accurate, but
in practice the most model dependent result for the intrinsic bolometric
luminosity of ISM is Lbol/SFR\sim 1.5x10^40 erg/s per Msun/yr. Assuming that
core collapse supernovae are the main source of energy, it implies that
\epsilon_SN\sim5x10^-2 (E_SN/10^51)^-1 of mechanical energy of supernovae is
converted into thermal energy of ISM.Comment: 15 pages, 8 figures, 3 tables - Accepted for publication in MNRA
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