Demonstrating Agreement between Radio and Fluorescence Measurements of the Depth of Maximum of Extensive Air Showers at the Pierre Auger Observatory.

We show, for the first time, radio measurements of the depth of shower maximum (X_{max}) of air showers induced by cosmic rays that are compared to measurements of the established fluorescence method at the same location. Using measurements at the Pierre Auger Observatory we show full compatibility between our radio and the previously published fluorescence dataset, and between a subset of air showers observed simultaneously with both radio and fluorescence techniques, a measurement setup unique to the Pierre Auger Observatory. Furthermore, we show radio X_{max} resolution as a function of energy and demonstrate the ability to make competitive high-resolution X_{max} measurements with even a sparse radio array. With this, we show that the radio technique is capable of cosmic-ray mass composition studies, both at Auger and at other experiments.

Limits to Gauge Coupling in the Dark Sector Set by the Nonobservation of Instanton-Induced Decay of Super-Heavy Dark Matter in the Pierre Auger Observatory Data.

Instantons, which are nonperturbative solutions to Yang-Mills equations, provide a signal for the occurrence of quantum tunneling between distinct classes of vacua. They can give rise to decays of particles otherwise forbidden. Using data collected at the Pierre Auger Observatory, we search for signatures of such instanton-induced processes that would be suggestive of super-heavy particles decaying in the Galactic halo. These particles could have been produced during the post-inflationary epoch and match the relic abundance of dark matter inferred today. The nonobservation of the signatures searched for allows us to derive a bound on the reduced coupling constant of gauge interactions in the dark sector: α_{X}≲0.09, for 10^{9}≲M_{X}/GeV<10^{19}. Conversely, we obtain that, for instance, a reduced coupling constant α_{X}=0.09 excludes masses M_{X}≳3×10^{13} GeV. In the context of dark matter production from gravitational interactions alone, we illustrate how these bounds are complementary to those obtained on the Hubble rate at the end of inflation from the nonobservation of tensor modes in the cosmological microwave background.

Retrieving cloud geometrical extents from MIPAS/ENVISAT measurements with a 2-D tomographic approach.

Clouds represent a critical factor in regulating the Earth's atmosphere and its energy balance. Satellite instruments can measure the energy balance and global atmospheric properties only through an accurate knowledge of the vertical profile of cloudiness, which is as yet one of the key shortages in atmospheric science. The Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) on-board the ENVISAT satellite, designed to infer the amount of atmospheric trace-gases, demonstrated also sensitivity to the radiation emitted from clouds. In order to model the effect of the geometrical extent of a cloud on MIPAS measurements, we developed a retrieval model capable to simulate cloud effects on broad spectral intervals accounting for the two-dimensional (2-D) variability of the atmosphere in the satellite orbit plane. The 2-D analysis revealed a sensitivity of MIPAS spectra to both the vertical and horizontal extents and the position of clouds along the instrument line of sight. One-dimensional models were found to underestimate Cloud Top Height (CTH) by approximating clouds as an infinite horizontal layer with a finite vertical extents. With the 2-D approach, we showed it is possible, for optically thin Polar Stratospheric Clouds (PSCs), to retrieve both CTH and horizontal dimension by analyzing simultaneously all the limb observations that come across the cloud with their field of view. For a selected case study we found a very good agreement for both PSC CTH and horizontal extents retrieved from MIPAS measurements and those retrieved from coincident CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarisation) measurements.

[Endoscopic rubber band ligation in treatment of esophageal varices bleeding. Personal experience]. / La legatura elastica nel trattamento endoscopico della emorragia da rottura di varici esofagee. Esperienza di un singolo centro.

INTRODUCTION: Bleeding esophageal varices is the most serious complication of the portal hypertension, and the greater cause of dead (25% of the patients). The survival after esophageal varices bleeding depends in wide part from the swiftness and effectiveness of hemostasis and from the degree of functional liver reserve. Aim of our manuscript is to report our experience about hemostasis bleeding esophageal varices with endoscopic rubber band ligation. PATIENTS AND METHODS: From January 1999 to January 2008 we performed 302 esofagogastroduodenoscopy (EGDS) for esophageal varices bleeding (M: F ratio = 1.4:1, mean age 56.4 years, 62% of cases with HCV-related cirrhosis, 29% alcoholic cirrhosis and 9% cryptogenic cirrhosis; 20% suffered from chronic renal failure, 15% diabetes mellitus, 10% hepatocellular carcinoma on cirrhosis, 5% systemic encephalopathy and 1% AIDS). RESULTS; All patients were treated within 6 hours after the first reported episode of haematemesis and all received beta-blocker therapy after the episode. In the first phase of our experience were used rechargeable elastic ligator and then multibyte, even in combination with polidocanol sclerotherapy (8%) or injection of cyanoacrylate (5%). The best results were achieved with band ligation, in terms of primitive haemostasis, rebleeding, (3%), intraoperative mortality (1%) and 6 weeks mortality (1%). CONCLUSION: To date, no single method applicable to all patients with bleeding esophageal varices, but endoscopic rubber band ligation is currently considered the first-line treatment of proper multidisciplinary approach to the patient, both during the acute event than prevention of rebleeding, because it is an effective, safe and repeatable, in experienced hands.

[Complications of elective esophago-gastro-duodenoscopy (EGDS). Personal experience and literature review]. / Le complicanze della esofagogastroduodenoscopia (egds) in elezione. Esperienza personale e revisione della letteratura.

INTRODUCTION: Although upper gastrointestinal (GI) endoscopy is reasonably safe, it is not perfectly so. The complication rate is about 0.1% for EGDS. Aim of this study is to schedule and evaluate all possible complications, starting from personal experience in Operative Unit of Surgical Endoscopy. PATIENTS AND METHODS: We evaluated all EGDS performed at the Operative Unit of Surgical Endoscopy of Policlinico in Palermo between January 2000 and January 2008. A single staff of endoscopists performed diagnostic and therapeutic exam. All complications were tabulated and scheduled to identify possible risk factors or indicators procedure- or patient-related. RESULTS: 5.258 patients (43.6 %) experienced temporary and self-limiting hypoxia (SaO2 < 85%); we report totally 18 complications (0.15%), according to literature data: 2 hypopharinx perforations (0.016%), 2 middle esophagus perforation (either with death of patients = 0.016%), 3 post-biopsy hematomas of the gastric wall (0.02%) and 2 duodenal wall (0.016%) 6 (0.04%) post-polypectomy bleeding, 1 abscess post-percutaneous endoscopic gastrostomy (PEG) (0.008%) and 1 accidentally PEG remove (0.008%). DISCUSSION: EGDS-related complications may occur and cannot be prevented completely even in expert hands however, early recognition and proper management will lead to better outcome. Because of the complexity of endoscopic procedures has increased, endoscopists need to be aware of all possible procedure-related complications and should use strategies to minimize it. CONCLUSIONS: Endoscopic complications will inevitably occur if an endoscopist does many procedures. The knowledge of potential complications and their expected frequency can lead to improved risk-benefit analysis by physicians and patients as well as true informed consent by patients. Early recognition of complications and prompt intervention may minimize patient morbidity.

Acute onset of esophageal duplication cyst in adult. Case report.

INTRODUCTION: Esophageal duplication (ED) cyst is unusual congenital disorder of the foregut, accounting for 10% to 15% of duplications of all foregut cysts. We report a case of esophageal duplication with acute clinical presentation, treated successfully with surgical resection. CASE REPORT: 46-year-old man with acute dysphagia and gastroesophageal reflux of 2 weeks duration, showed submucosal bulging mass in the posterior wall of the middle third of oesophagus, fluid-filled cystic structure, dyshomogeneous, low-attenuation mass with smooth borders compatible with an hemorrhagic esophageal duplication cyst. With the suspect of acute presentation of a complicated esophageal cyst, the patient underwent surgery by right posterolateral thoracotomy. A gastrografin esophagogram was performed on third postoperative day and showed no leaks. DISCUSSION: Up to 80% of the esophageal duplication cysts are diagnosed in childhood and the majority of young patients develop symptoms, while symptomatic cyst into adult life is very rare (<7%). Acute onset is generally due to complications, i.e. intracystic hemorrhage, perforation, and infection, especially of the cyst with esophageal communication. Complete surgical excision by thoracotomy or thoracoscopy is the therapy of choice even if the patient is asymptomatic because of the risk of complications such as aspiration and bleeding. CONCLUSIONS: The diagnosis and treatment of esophageal cysts is still evolving. The pathological diagnosis of oesophageal duplication requires the presence of the Ladd and Gross criteria. The infrequent acute onset doesn't modify the management and the surgical resection is the procedure of choice. The future of the treatment of esophageal cysts lies in the advancement of minimally invasive operative techniques.

[Endoscopic surveillance of colon-rectum in the narrow band imaging era]. / Sorveglianza endoscopica del colon-retto. Ruolo del Narrow Band Imaging (NBI).

BACKGROUND AND AIMS: Colonoscopic surveillance is an established method of colorectal cancer (CRC) screening that reduces death rates, but has an adenoma miss rate of 10-20%. Narrow band imaging (NBI), a novel endoscopic technology, highlights superficial mucosal capillaries and improves contrast for small adenomas. This study evaluated the role of NBI in the improving colon adenoma detection. PATIENTS AND METHODS: White light colonoscope was compared with NBI for adenoma detection during colonoscopy. 120 patients presenting for diagnostic colonoscopy were randomly assigned to undergo colonoscopy using either conventional white light or NBI colonscope during instrument withdrawal. The outcome parameter was the difference in the adenoma detection rate between the two techniques. All polyps detected were removed for histopathological analysis. RESULTS: Adenomas were detected more frequently in the NBI group (51) than in the control group (49); however, the difference was not statistically significant (p = 0.128). The extubation time was significatively longer in the NBI group (p = 0.003). CONCLUSIONS: In our experience, the NBI did not increased the adenomas detection rate compared to white light by an endoscopist with a known high detection rate using white light.

[Mechanical versus manual anastomoses in colorectal surgery. Personal experience]. / Anastomosi meccaniche versus anastomosi manuali nella chirurgia del retto. Esperienza personale

BACKGROUND: The diffusion in the years '80 of the stapler has modified the habits of the surgeons, determining the reduction of the operative time in colorectal surgery and the possibility to operate cancer of lower rectum, but leaving unchanged the rates of postoperative complications and bringing to the footlights some new complications. Aim of paper is to report our experience about of mechanical sutures in the colorectal anastomoses, with particular attention to the risk factors and complications procedure-related. PATIENTS AND METHOD: From January 2000 to January 2006 in the Section of General and Thoracic Surgery of the University in Palermo, 26 stapled colorectal anastomosis and 11 mechanical terminal colostomies after Miles' amputation have been performed; 12 patients have been submitted to low colorectal termino-terminal anastomosis, 6 to termino-terminal ultralow anastomosis, 1 to coloanal anastomosis and 7 to Knight-Griffen technique. RESULTS: We registered 2 anastomotic dehiscences (8%), 3 (12%) anastomotic bleeding and one anastomotic stenosis (4%) 12 months after surgery. No mortality procedure-related took place. DISCUSSION: From the literature review emerges the absence of statistically differences between manual and mechanical suture in the colorectal anastomosis in terms of mortality, morbidity (clinical and radiological incidence of the anastomotic gaps, anastomotic stenosis, redo, bleeding, infection of the wound) of employed time to make the anastomosis and of staying in hospital. These data are from American Schools, while greater incidence of radiological leakage is recorded in the European schools is for the manual suture. CONCLUSIONS: At present does not exist clinical trial that shows the superiority of mechanical stapling versus manual suture in the colorectal anastomosis. Stapler makes possible the lower colo-rectal anastomosis often avoiding abdomino-perineal amputation of the rectum, with better quality of life and oncological radicality, but increasing however the incidence of complications as anastomotic dehiscence and stenosis, even if not statistically significant.

Endoscopic cytology in biliary strictures. Personal experience.

INTRODUCTION: The differential diagnosis between malignant and benign biliary strictures is the cornerstone of the management of jaundiced patients. The aim of our study is to define the role of cytology of the bile withdrawn during endoscopic retrograde cholangiopancreatography (ERCP), to reach a diagnosis of the nature of biliary stricture. PATIENTS AND METHODS: This retrospective study was conducted on 67 consecutive patients affected of ingravescent obstructive jaundice who underwent ERCP+/-PTE (percutaneous transhepatic endoscopic)+bile withdrawn+stenting. We founded hilar stricture in 21 patients (31.3%), middle third the common duct stricture in 17 (25.3%), and lower third stricture in 28 patients (41.4%). In one patient (2%) the cholangiography did not show any stricture, but we continued with the withdrawn of bile after positioning a naso-biliary drainage. RESULTS: Diagnosis was made in only 40 of 65 patients (61.5%) and no epithelial lining cells of the biliary tree was found in the remaining 25 patients (38.5%). The presence of neoplasm in the pancreato-biliary tract was excluded (absence of malignant cells) in 25 of 40 diagnostic exams (62.5%). During follow-up only 7 of these 25 patients resulted in having a benign disease (true negatives 28%) while the remaining 18 cases were diagnosed with malignant neoplasm of the pancreato-biliary tract (false negatives 72%). Nine of 14 with positive cytology for carcinoma were diagnosed with cholangiocarcinoma (65%), 4 with pancreatic (28%) and 1 with ampullary carcinoma. Of 25 non-diagnostic samples, 5 (20%) resulted as benign, 20 (80%) as malignant. The statistical analysis by chi-square test allowed us to conclude that bile cytology, if diagnostic, is significantly valid in identifying carcinoma of the pancreato-biliary tract (p<0.05) instead, considering the high rate of non diagnostic samples, its meaning is limited (p=0.09). DISCUSSION: Exfoliative cytology of bile samples obtained during ERCP is easier and less invasive method to determine the diagnosis of biliary strictures, but due to its low sensibility, varying from 6 to 63%, it doesn't appear accurate to establish a definite diagnosis; the stricture dilatation before the withdrawal increases the diagnostic sensibility and accuracy of the cytological exam. CONCLUSION: Bile withdrawn for cytology during ERCP is a safe method with no increasing in patient's morbidity. It allows a diagnostic orientation in 75% of the patients. Bile withdrawn after dilatation of stricture allows improves sensibility and accuracy. Negative results does not exclude malignant disease, however, if positive, it is considered diagnostic (positive predictive value 100%).

Juxtapapillary duodenal diverticular bezor as an exceptional cause of biliary stent obstruction. Case report.

INTRODUCTION: we describe the first case in literature of biliary stent obstruction by bezoar impaction in a iuxtapapillary duodenal diverticulum. CASE REPORT: this case illustrates an juxtapapillary duodenal diverticulum and bezoar in it causing obstructive jaundice in subject with two biliary stents for cholangiocarcinoma (Klatskin's tumor) in the absence of bile duct stones. RESULT: successful treatment with endoscopic stent removal and diverticulum toilette. Obstructive jaundice was cured after endoscopic removal of the bezoar and stent substitution. DISCUSSION: the presence of a bezoar and its possible contribution to the pathogenesis of pancreatitis in the presence of periampullary extraluminal duodenal diverticula makes endoscopic intervention for removal of the bezoar necessary and effective. CONCLUSIONS: biliary bezoar is a very rare but treatable cause of stents obstruction in patients with juxtapapillary duodenal diverticula. Endoscopic retrograde cholangiopancreatografhy is helpful in making diagnosis and for resolutive treatment.

Observation of intrinsically bright terrestrial gamma ray flashes from the Mediterranean basin.

We present three terrestrial gamma ray flashes (TGFs) observed over the Mediterranean basin by the Reuven Ramaty High Energy Solar Spectroscope Imager (RHESSI) satellite. Since the occurrence of these events in the Mediterranean region is quite rare, the characterization of the events was optimized by combining different approaches in order to better define the cloud of origin. The TGFs on 7 November 2004 and 16 October 2006 came from clouds with cloud top higher than 10-12 km where often a strong penetration into the stratosphere is found. This kind of cloud is usually associated with heavy precipitation and intense lightning activity. Nevertheless, the analysis of the cloud type based on satellite retrievals shows that the TGF on 27 May 2004 was produced by an unusual shallow convection. This result appears to be supported by the model simulation of the particle distribution and phase in the upper troposphere. The TGF on 7 November 2004 is among the brightest ever measured by RHESSI. The analysis of the energy spectrum of this event is consistent with a production altitude ≤12 km, which is in the upper part of the cloud, as found by the meteorological analysis of the TGF-producing thunderstorm. This event must be unusually bright at the source in order to produce such a strong signal in RHESSI. We estimate that this TGF must contain ∼3 × 1018 initial photons with energy >1 MeV. This is 1 order of magnitude brighter than earlier estimations of an average RHESSI TGF.