The IceCube neutrino detector is built into the Antarctic ice sheet at the South Pole to measure high energy neutrinos. For this, 4800 photomultiplier tubes (PMTs) are being deployed at depths ...between 1450 and 2450 meters into the ice to measure neutrino induced charged particles like muons. IceTop is a surface air shower detector consisting of 160 Cherenkov ice tanks located on top of IceCube. To extend IceTop, a radio air shower detector could be built to significantly increase the sensitivity at higher shower energies and for inclined showers. As air showers induced by cosmic rays are a major part of the muonic background in IceCube, IceTop is not only an air shower detector, but also a veto to reduce the background in IceCube. Air showers are detectable by radio signals with a radio surface detector. The major emission process is the coherent synchrotron radiation emitted by e+ e- shower particles in the Earths magnetic field (geosynchrotron effect). Simulations of the expected radio signals of air showers are shown. The sensitivity and the energy threshold of different antenna field configurations are estimated.
We report on studies of the viability and sensitivity of the Askaryan Radio Array (ARA), a new initiative to develop a Teraton-scale ultra-high energy neutrino detector in deep, radio-transparent ice ...near Amundsen-Scott station at the South Pole. An initial prototype ARA detector system was installed in January 2011, and has been operating continuously since then. We report on studies of the background radio noise levels, the radio clarity of the ice, and the estimated sensitivity of the planned ARA array given these results, based on the first five months of operation. Anthropogenic radio interference in the vicinity of the South Pole currently leads to a few-percent loss of data, but no overall effect on the background noise levels, which are dominated by the thermal noise floor of the cold polar ice, and galactic noise at lower frequencies. We have also successfully detected signals originating from a 2.5 km deep impulse generator at a distance of over 3 km from our prototype detector, confirming prior estimates of kilometer-scale attenuation lengths for cold polar ice. These are also the first such measurements for propagation over such large slant distances in ice. Based on these data, ARA-37, the 200 km^2 array now under construction, will achieve the highest sensitivity of any planned or existing neutrino detector in the 10^{16}-10^{19} eV energy range.
We present the results for a search of high-energy muon neutrinos with the IceCube detector in coincidence with the Crab nebula flare reported on September 2010 by various experiments. Due to the ...unusual flaring state of the otherwise steady source we performed a prompt analysis of the 79-string configuration data to search for neutrinos that might be emitted along with the observed gamma-rays. We performed two different and complementary data selections of neutrino events in the time window of 10 days around the flare. One event selection is optimized for discovery of E(sub nu)(sup -2) neutrino spectrum typical of 1st order Fermi acceleration. A similar event selection has also been applied to the 40-string data to derive the time-integrated limits to the neutrino emission from the Crab 35. The other event selection was optimized for discovery of neutrino spectra with softer spectral index and TeV energy cut-offs as observed for various galactic sources in gamma-rays. The 90% CL best upper limits on the Crab flux during the 10 day flare are 4.73 x 10(exp -11) per square centimeter per second TeV (sup -1) for an E(sub nu) (sup -2) neutrino spectrum and 2.50 x 10(exp -10) per square centimeter per second TeV(sup -1) for a softer neutrino spectra of E(sub nu)(sup -2.7), as indicated by Fermi measurements during the flare. IceCube has also set a time-integrated limit on the neutrino emission of the Crab using 375.5 days of livetime of the 40-string configuration data. This limit is compared to existing models of neutrino production from the Crab and its impact on astrophysical parameters is discussed. The most optimistic predictions of some models are already rejected by the IceCube neutrino telescope with more than 90% CL.
Context. Transient neutrino sources such as Gamma-Ray Bursts (GRBs) and Supernovae (SNe) are hypothesized to emit bursts of high-energy neutrinos on a time-scale of < or approx.100 s. While GRB ...neutrinos would be produced in high relativistic jets, core-collapse SNe might host soft-relativistic jets, which become stalled in the outer layers of the progenitor star leading to an efficient production of high-energy neutrinos. Aims. To increase the sensitivity to these neutrinos and identify their sources, a low-threshold optical follow-up program for neutrino multiplets detected with the IceCube observatory has been implemented. Methods. If a neutrino multiplet, i.e. two or more neutrinos from the same direction within 100 s, is found by IceCube a trigger is sent to the Robotic Optical Transient Search Experiment, ROTSE. The 4 ROTSE telescopes immediately start an observation program of the corresponding region of the sky in order to detect an optical counterpart to the neutrino events. Results. No statistically significant excess in the rate of neutrino multiplets has been observed and furthermore no coincidence with an optical counterpart was found. Conclusions. The search allows, for the first time, to set stringent limits on current models predicting a high-energy neutrino flux from soft relativistic hadronic jets in core-collapse SNe. We conclude that a sub-population of SNe with typical Lorentz boost factor and jet energy of 10 and 3 x 10(exp 51) erg, respectively, does not exceed 4:2% at 90% confidence.
In this paper we report the first observation in the Southern hemisphere of an energy dependence in the Galactic cosmic ray anisotropy up to a few hundred TeV. This measurement was performed using ...cosmic ray induced muons recorded by the partially deployed IceCube observatory between May 2009 and May 2010. The data include a total of 33x l0(epx 9) muon events with a median angular resolution of approx 3 degrees. A sky map of the relative intensity in arrival direction over the Southern celestial sky is presented for cosmic ray median energies of 20 and 400 Te V. The same large-scale anisotropy observed at median energies around 20 TeV is not present at 400 TeV. Instead, the high energy skymap shows a different anisotropy structure including a deficit with a post-trial significance of -6.30 sigma. This anisotropy reveals a new feature of the Galactic cosmic ray distribution, which must be incorporated into theories of the origin and propagation of cosmic rays.
Recent observations of GeV /TeV photon emission from several X-ray binaries have sparked a renewed interest in these objects as galactic particle accelerators. In spite of the available ...multi-wavelength data, their acceleration mechanisms are not determined, and the nature of the accelerated particles (hadrons or leptons) is unknown. While much evidence favors leptonic emission, it is very likely that a hadronic component is also accelerated in the jets of these binary systems. The observation of neutrino emission would be clear evidence for the presence of a hadronic component in the outflow of these sources. In this paper we look for periodic neutrino emission from binary systems. Such modulation, observed in the photon flux, would be caused by the geometry of these systems. The results of two searches are presented that differ in the treatment of the spectral shape and phase of the emission. The 'generic' search allows parameters to vary freely and best fit values, in a 'model-dependent' search, predictions are used to constrain these parameters. We use the IceCube data taken from May 31, 2007 to April 5, 2008 with its 22-string configuration, and from April 5, 2008 and May 20, 2009 with its 40-string configuration. For the generic search and the 40 string sample, we find that the most significant source in the catalog of 7 binary stars is Cygnus X-3 with a 1.8% probability after trials (2.10" sigma one-sided) of being produced by statistical fluctuations of the background. The model-dependent method tested a range of system geometries - the inclination and the massive star's disk size - for LS I+61 deg 303, no significant excess was found.
The presence of detrusor muscle is essential for accurate staging of T1 cancers. Detrusor muscle presence can be a quality indicator of transurethral resection of bladder tumor for nonmuscle invasive ...bladder cancer. We hypothesized that increasing surgeon awareness of personal and institutional detrusor muscle sampling rates could improve resection quality and long-term oncologic outcomes.
A retrospective review of transurethral resections of bladder tumor from 1/2006 to 2/2018 was performed. The presence of detrusor muscle in the pathology report and transurethral resection specimen were extracted from records. Individual surgeon scorecards were created and distributed. Rates of detrusor muscle sampling were compared prior to and 12 months after distribution. Chart review was done to compare 3-year recurrence and progression outcomes before and after distribution of scorecards.
The rate of detrusor muscle sampling increased from 36% (1,250/3,488) to 54% (202/373) (p=0.001) in the 12 months after scorecard distribution, ie from 30% (448/1,500) to 55% (91/165) (p <0.001) in Ta tumors and from 47% (183/390) to 72% (42/58) (p <0.001) in T1 tumors. Pathological reporting of muscle also improved for all samples (73%, 2,530/3,488 to 90%, 334/373, p <0.001), Ta (75%, 1,127/1,500 to 94%, 155/165, p <0.001) and T1 (93%, 362/390 to 100%, 58/58, p=0.04). On multivariate Cox regression analysis, the surgeon scorecard was associated with decreased 3-year risk of recurrence (HR 0.63, 95% CI 0.40-0.99).
Creation and distribution of individual surgeon scorecards improved detrusor muscle sampling on transurethral resection and was associated with decreased risk of disease recurrence. Quality evaluation of transurethral resection of bladder tumor may contribute to improved outcomes of patients with nonmuscle invasive bladder cancer.
We present the largest, most comprehensive, single center experience to date of minimally invasive liver resection (MILR).
Despite anecdotal reports of MILR, few large single center reports have ...examined these procedures by comparing them to their open counterparts.
Three hundred MILR were performed between July 2001 and November 2006 at our center for both benign and malignant conditions. These included 241 pure laparoscopic, 32 hand-assisted laparoscopic, and 27 laparoscopy-assisted open (hybrid) resections.These MILR were compared with 100 contemporaneous, cohort-matched open resections. MILR included segmentectomies (110), bisegmentectomies (63), left hepatectomies (47), right hepatectomies (64), extended right hepatectomies (8), and caudate lobe (8) resections. Benign etiologies encompassed cysts (70), hemangiomata (37), focal nodular hyperplasia (FNH) (23), adenomata (47), and 20 live donor right lobectomies. Malignant etiologies included primary (43) and metastatic (60) tumors. Hepatic fibrosis/cirrhosis was present in 25 of 103 patients with malignant diseases (24%).
There was high data consistency within the 3 types of MILR. MILR compared favorably with standard open techniques: operative times (99 vs. 182 minutes), blood loss (102 vs. 325 ml), transfusion requirement (2 of 300 vs. 8 of 100), length of stay (1.9 vs. 5.4 days), overall operative complications (9.3% vs. 22%), and local malignancy recurrence (2% vs. 3%). No port-site recurrences occurred. Conversion from laparoscopic to hand-assisted laparoscopic resection occurred in 20 patients (6%), with no conversions to open. No hand-assisted procedures were converted to open, but 2 laparoscopy-assisted (7%) were converted to open.
Our data show that MILR outcomes compare favorably with those of the open standard technique. Our experience suggests that MILR of varying magnitudes is safe and effective for both benign and malignant conditions.
To report the technical success of image and endoscopy-guided retrograde trans-urostomy urinary drainage as a primary catheter placement method performed by interventional radiology (IR).
Nine ...patients (15 attempted drain placements) with ureteric obstruction following radical cystectomy and urostomy creation were included. The patients were referred to IR for urinary drainage. All patients underwent primary image and endoscopy-guided retrograde trans-urostomy urinary drainage.
Primary image and endoscopy-guided retrograde trans-urostomy urinary drainage was successful in 13/15 (86.6%) attempts. The proposed technique had a limited complication rate omitting the percutaneous nephrostomy access step.
Primary image and endoscopy guided retrograde trans-urostomy urinary drainage should be considered before percutaneous nephrostomy in all patients with a urostomy.
•The feasibility of endoscopic guided ureteric stenting performed solely by IR.•The importance of integration of endoscopic guided interventions in IR training.•Endoscopic guidance can preclude invasive interventions during ureteric stenting.
Purpose The adoption of active surveillance varies widely across urological communities, which suggests a need for more consistency in the counseling of patients. To address this need we used the ...RAND/UCLA Appropriateness Method to develop appropriateness criteria and counseling statements for active surveillance. Materials and Methods Panelists were recruited from MUSIC urology practices. Combinations of parameters thought to influence decision making were used to create and score 160 theoretical clinical scenarios for appropriateness of active surveillance. Recent rates of active surveillance among real patients across the state were assessed using the MUSIC registry. Results Low volume Gleason 6 was deemed highly appropriate for active surveillance whereas high volume Gleason 6 and low volume Gleason 3+4 were deemed appropriate to uncertain. No scenario was deemed inappropriate or highly inappropriate. Prostate specific antigen density, race and life expectancy impacted scores for intermediate and high volume Gleason 6 and low volume Gleason 3+4. The greatest degree of score dispersion (disagreement) occurred in scenarios with long life expectancy, high volume Gleason 6 and low volume Gleason 3+4. Recent rates of active surveillance use among real patients ranged from 0% to 100% at the provider level for low or intermediate biopsy volume Gleason 6, demonstrating a clear opportunity for quality improvement. Conclusions By virtue of this work urologists have the opportunity to present specific recommendations from the panel to their individual patients. Community-wide efforts aimed at increasing rates of active surveillance and reducing practice and physician level variation in the choice of active surveillance vs treatment are warranted.
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