The Payload for Ultrahigh Energy Observations (PUEO) long-duration balloon experiment is designed to have world-leading sensitivity to ultrahigh-energy neutrinos at energies above 1 EeV. Probing this ...energy region is essential for understanding the extreme-energy universe at all distance scales. PUEO leverages experience from and supersedes the successful Antarctic Impulsive Transient Antenna (ANITA) program, with an improved design that drastically improves sensitivity by more than an order of magnitude at energies below 30 EeV. PUEO will either make the first significant detection of or set the best limits on ultrahigh-energy neutrino fluxes.
We report the observation of 16 cosmic ray events with a mean energy of 1.5 × 10¹⁹ eV via radio pulses originating from the interaction of the cosmic ray air shower with the Antarctic geomagnetic ...field, a process known as geosynchrotron emission. We present measurements in the 300-900 MHz range, which are the first self-triggered, first ultrawide band, first far-field, and the highest energy sample of cosmic ray events collected with the radio technique. Their properties are inconsistent with current ground-based geosynchrotron models. The emission is 100% polarized in the plane perpendicular to the projected geomagnetic field. Fourteen events are seen to have a phase inversion due to reflection of the radio beam off the ice surface, and two additional events are seen directly from above the horizon. Based on a likelihood analysis, we estimate angular pointing precision of order 2° for the event arrival directions.
Caspases are a family of cysteine proteases implicated in the biochemical and morphological changes that occur during apoptosis (programmed cell death). The loop domain of Bcl-2 is cleaved at Asp34 ...by caspase-3 (CPP32) in vitro, in cells overexpressing caspase-3, and after induction of apoptosis by Fas ligation and interleukin-3 withdrawal. The carboxyl-terminal Bcl-2 cleavage product triggered cell death and accelerated Sindbis virus-induced apoptosis, which was dependent on the BH3 homology and transmembrane domains of Bcl-2. Inhibitor studies indicated that cleavage of Bcl-2 may further activate downstream caspases and contribute to amplification of the caspase cascade. Cleavage-resistant mutants of Bcl-2 had increased protection from interleukin-3 withdrawal and Sindbis virus-induced apoptosis. Thus, cleavage of Bcl-2 by caspases may ensure the inevitability of cell death.
SN 2007it is a bright, Type IIP supernova which shows indications of both pre-existing and newly formed dust. The visible photometry shows a bright late-time luminosity, powered by the 0.09 M of 56Ni ...present in the ejecta. There is also a sudden drop in optical brightness after day 339, and a corresponding brightening in the IR due to new dust forming in the ejecta. CO and SiO emission, generally thought to be precursors to dust formation, may have been detected in the mid-IR photometry of SN 2007it. The optical spectra show stronger than average O I emission lines and weaker than average Ca II lines, which may indicate a 16-27 M progenitor, on the higher end of expected Type IIP masses. Multi-component O I lines are also seen in the optical spectra, most likely caused by an asymmetric blob or a torus of oxygen core material being ejected during the SN explosion. Interaction with circumstellar material prior to day 540 may have created a cool dense shell between the forward and reverse shocks where new dust is condensing. At late times there is also a flattening of the visible light curve as the ejecta luminosity fades and a surrounding light echo becomes visible. Radiative transfer models of SN 2007it spectral energy distributions indicate that up to 10--4 M of new dust has formed in the ejecta, which is consistent with the amount of dust formed in other core-collapse supernovae.
SN 2007od exhibits characteristics that have rarely been seen in a Type IIP supernova (SN). Optical V-band photometry reveals a very steep brightness decline between the plateau and nebular phases of ...{approx}4.5 mag, likely due to SN 2007od containing a low mass of {sup 56}Ni. The optical spectra show an evolution from normal Type IIP with broad H{alpha} emission, to a complex, four-component H{alpha} emission profile exhibiting asymmetries caused by dust extinction after day 232. This is similar to the spectral evolution of the Type IIn SN 1998S, although no early-time narrow ({approx}200 km s{sup -1}) H{alpha} component was present in SN 2007od. In both SNe, the intermediate-width H{alpha} emission components are thought to arise in the interaction between the ejecta and its circumstellar medium (CSM). SN 2007od also shows a mid-infrared excess due to new dust. The evolution of the H{alpha} profile and the presence of the mid-IR excess provide strong evidence that SN 2007od formed new dust before day 232. Late-time observations reveal a flattening of the visible light curve. This flattening is a strong indication of the presence of a light echo, which likely accounts for much of the broad, underlying H{alpha} component seen at late times. We believe that the multi-peaked H{alpha} emission is consistent with the interaction of the ejecta with a circumstellar ring or torus (for the inner components at {+-}1500 km s{sup -1}) and a single blob or cloud of circumstellar material out of the plane of the CSM ring (for the outer component at -5000 km s{sup -1}). The most probable location for the formation of new dust is in the cool dense shell created by the interaction between the expanding ejecta and its CSM. Monte Carlo radiative transfer modeling of the dust emission from SN 2007od implies that up to {approx}4 x 10{sup -4} M{sub sun} of new dust has formed. This is similar to the amounts of dust formed in other core-collapse supernovae such as SNe 1999em, 2004et, and 2006jc.
Background Complete macroscopic tumor resection is one of the most relevant predictors of long-term survival in pancreatic ductal adenocarcinoma. Because locally advanced pancreatic tumors can ...involve adjacent organs, “extended” pancreatectomy that includes the resection of additional organs may be needed to achieve this goal. Our aim was to develop a common consistent terminology to be used in centers reporting results of pancreatic resections for cancer. Methods An international panel of pancreatic surgeons working in well-known, high-volume centers reviewed the literature on extended pancreatectomies and worked together to establish a consensus on the definition and the role of extended pancreatectomy in pancreatic cancer. Results Macroscopic (R1) and microscopic (R0) complete tumor resection can be achieved in patients with locally advanced disease by extended pancreatectomy. Operative time, blood loss, need for blood transfusions, duration of stay in the intensive care unit, and hospital morbidity, and possibly also perioperative mortality are increased with extended resections. Long-term survival is similar compared with standard resections but appears to be better compared with bypass surgery or nonsurgical palliative chemotherapy or chemoradiotherapy. It was not possible to identify any clear prognostic criteria based on the specific additional organ resected. Conclusion Despite increased perioperative morbidity, extended pancreatectomy is warranted in locally advanced disease to achieve long-term survival in pancreatic ductal adenocarcinoma if macroscopic clearance can be achieved. Definitions of extended pancreatectomies for locally advanced disease (and not distant metastatic disease) are established that are crucial for comparison of results of future trials across different practices and countries, in particular for those using neoadjuvant therapy.
We report initial results of the first flight of the Antarctic Impulsive Transient Antenna (ANITA-1) 2006-2007 Long Duration Balloon flight, which searched for evidence of a diffuse flux of cosmic ...neutrinos above energies of E(nu) approximately 3 x 10(18) eV. ANITA-1 flew for 35 days looking for radio impulses due to the Askaryan effect in neutrino-induced electromagnetic showers within the Antarctic ice sheets. We report here on our initial analysis, which was performed as a blind search of the data. No neutrino candidates are seen, with no detected physics background. We set model-independent limits based on this result. Upper limits derived from our analysis rule out the highest cosmogenic neutrino models. In a background horizontal-polarization channel, we also detect six events consistent with radio impulses from ultrahigh energy extensive air showers.
Background This position statement was developed to expedite a consensus on definition and treatment for borderline resectable pancreatic ductal adenocarcinoma (BRPC) that would have worldwide ...acceptability. Methods An international panel of pancreatic surgeons from well-established, high-volume centers collaborated on a literature review and development of consensus on issues related to borderline resectable pancreatic cancer. Results The International Study Group of Pancreatic Surgery (ISGPS) supports the National Comprehensive Cancer Network criteria for the definition of BRPC. Current evidence supports operative exploration and resection in the case of involvement of the mesentericoportal venous axis; in addition, a new classification of extrahepatic mesentericoportal venous resections is proposed by the ISGPS. Suspicion of arterial involvement should lead to exploration to confirm the imaging-based findings. Formal arterial resections are not recommended; however, in exceptional circumstances, individual therapeutic approaches may be evaluated under experimental protocols. The ISGPS endorses the recommendations for specimen examination and the definition of an R1 resection (tumor within 1 mm from the margin) used by the British Royal College of Pathologists. Standard preoperative diagnostics for BRPC may include: (1) serum levels of CA19-9, because CA19-9 levels predict survival in large retrospective series; and also (2) the modified Glasgow Prognostic Score and the neutrophil/lymphocyte ratio because of the prognostic relevance of the systemic inflammatory response. Various regimens of neoadjuvant therapy are recommended only in the setting of prospective trials at high-volume centers. Conclusion Current evidence justifies portomesenteric venous resection in patients with BRPC. Basic definitions were identified, that are currently lacking but that are needed to obtain further evidence and improvement for this important patient subgroup. A consensus for each topic is given.
We report on observations of coherent, impulsive radio Cherenkov radiation from electromagnetic showers in solid ice. This is the first observation of the Askaryan effect in ice. As part of the ...complete validation process for the ANITA experiment, we performed an experiment at the Stanford Linear Accelerator Center in June 2006 using a 7.5 metric ton ice target. We measure for the first time the large-scale angular dependence of the radiation pattern, a major factor in determining the solid-angle acceptance of ultrahigh-energy neutrino detectors.
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