Probe of unparticles at the LHC in exclusive two lepton and two photon production via photon-photon fusion

The exclusive production pp->pXp is known to be one of the most clean channels at the LHC. We investigate the potential of processes pp -> p l-l+ p and pp-> p gamma gamma p to probe scalar and tensor unparticles by considering three different forward detector acceptances; 0.0015<xi<0.15, 0.0015<xi<0.5 and 0.1<xi<0.5. We obtain 95% confidence level sensitivity limits on the unparticle couplings for various integrated luminosities.Comment: 27 pages, 17 figure

The effect of electromagnetic properties of neutrinos on the photon-neutrino decoupling temperature

We examine the impact of electromagnetic properties of neutrinos on the annihilation of relic neutrinos with ultra high energy cosmic neutrinos for the $\nu \bar{\nu}\to \gamma\gamma$ process. For this process, photon-neutrino decoupling temperature is calculated via effective lagrangian model beyond the standard model. We find that photon-neutrino decoupling temperature can be importantly reduced below the QCD phase transition with the model independent analysis defining electromagnetic properties of neutrinos.Comment: 12 pages, 3 figures, published versio

Visual clues act as a substitute for haptic feedback in robotic surgery

Objective: The lack of haptic feedback (HF) in robotic surgery is one of the major concerns of novice surgeons to that field. The superior visual appearances acquired during robotic surgery may give clues that make HF less important. Methods: We surveyed 52 individuals on their perception of HF during robotic surgery. The first group of 34 surgically inexperienced people used the da Vinci robot for their first time (drylab). The second group included 8 laparoscopic surgeons with experience up to a fifth robotic operation. The third group included 10 surgical experts with substantial experience (150-650 robotic cases). Visual analog assessment was made of perception of HF, how much HF was missed, how much the absence of HF impaired the operators' level of comfort. Robotic experts were asked if complications have occurred as a result of a lack of HF. Results: Of the first group, 50% reported the perception of HF, as did 55% of the second group and 100% of the third group (difference between group 1 and group 3: p<0.05). The first group missed HF for 6.5; the second group for 4.3, and the third group for 4 (difference between groups 1 and 3: p<0.05). The surgical experts claimed to have missed HF for 7.2 s when they first started robotic surgery (Difference to now: p<0.05). The lack of HF caused discomfort for the first group of 4; for the second group of 4,4, and for the third group of 2,6. One complication was reported by the robotic experts as resulting from the lack of HF. Conclusions: The data support the conclusion that even beginners quickly experience the perception of HF when performing robotic surgery. With more experience, perception of HF and the level of comfort with robotic surgery increases significantly. This perception of HF makes "real” HF less important and demonstrates that its importance is overestimated by novices in robotic surger

High fidelity, radiation tolerant analog-to-digital converters

Techniques for an analog-to-digital converter (ADC) using pipeline architecture includes a linearization technique for a spurious-free dynamic range (SFDR) over 80 deciBels. In some embodiments, sampling rates exceed a megahertz. According to a second approach, a switched-capacitor circuit is configured for correct operation in a high radiation environment. In one embodiment, the combination yields high fidelity ADC (>88 deciBel SFDR) while sampling at 5 megahertz sampling rates and consuming <60 milliWatts. Furthermore, even though it is manufactured in a commercial 0.25-.mu.m CMOS technology (1 .mu.m=12.sup.-6 meters), it maintains this performance in harsh radiation environments. Specifically, the stated performance is sustained through a highest tested 2 megarad(Si) total dose, and the ADC displays no latchup up to a highest tested linear energy transfer of 63 million electron Volts square centimeters per milligram at elevated temperature (131 degrees C.) and supply (2.7 Volts, versus 2.5 Volts nominal)

Laparoscopic versus open resection for appendix carcinoid

Background: Since an increasing number of appendectomies are performed via laparoscopy, it is crucial to determine the impact of this approach on appendix carcinoid (AC) outcome. The goal of this study was to compare results of laparoscopic (LAP) versus open (OP) appendectomy for AC according to intend to treat approach. Methods: A retrospective review (1991-2003) identified 39 patients (median age, 36 years; range, 12-83) treated by laparoscopy (LAP) or laparotomy (OP) for AC in a single institution. Follow-up was complete for all patients (median, 67 months; range, 4-132). Results: Most cases had associated acute appendicitis (64%). Median carcinoid size was 1.1 cm (range, 0.3-5) and 0.4 cm (range, 0.2-3) in the LAP and OP groups, respectively. LAP and OP were performed in 21 (54%) and 18 (46%) patients, respectively. Surgical margins were positive in two patients in the LAP group and one patient in the OP group (p = 0.6). Right colectomies were performed for AC >2 cm in five patients after LAP and in four patients after OP (p = 0.9). Actuarial 5-year survival rates were 100 and 94% in the LAP and OP groups, respectively (p = 0.2). Two patients died in the OP group, one due to metastatic carcinoid and the other due to metachronous colorectal cancer. Synchronous or metachronous colorectal carcinomas developed in six patients (15%). Conclusion: Laparoscopic appendectomy is a safe procedure for AC, with carcinologic and long-term results similar to those of conventional appendectomy. Thus, pre- or per-operative suspicion of AC is not a contraindication to LAP. Prognosis of AC appears more dependent on carcinoid malignant potential or associated tumors. Risk for developing colorectal adenocarcinoma is high in AC patients and warrants follow-up of all patients with colonoscopic screenin

Risk factors for mortality-morbidity after emergency-urgent colorectal surgery

Background: The aim of this study was to assess the risk factors associated with mortality and morbidity following emergency or urgent colorectal surgery. Materials and methods: All data regarding the 462 patients who underwent emergency colonic resection in our institution between November 2002 and December 2007 were prospectively entered into a computerized database. Results: The median age of patients was 73 (range 17-98)years. The most common indications for surgery were: 171 adenocarcinomas (37%), 129 complicated diverticulitis (28%), and 35 colonic ischemia (7.5%). Overall mortality and morbidity rates were 14% and 36%, respectively. In multivariate analysis, the only parameter significantly associated with postoperative mortality was blood loss >500cm3 (odds ratio (OR) = 3.33, 95% confidence interval (CI) 1.63-6.82, p = 0.001). There were three parameters which correlated with postoperative morbidity: ASA score ≥3 (OR = 2.9, 95% CI 1.9-4.5, p < 0.001), colonic ischemia (OR = 3.4, 95% CI 1.4-7.7, p = 0.006), and stoma creation (OR = 2.2, 95% CI 1.4-3.4, p = 0.0003). Conclusions: The main risk factors for postoperative morbidity and mortality following emergency colorectal surgery are related to: (1) patients' ASA score, (2) colonic ischemia, and (3) perioperative bleeding. These variables should be considered in the elaboration of future scoring systems to predict outcome of emergency colorectal surger

Probe of extra dimensions in gamma q->gamma q at the LHC

We have examined TeV scale effects of extra spatial dimensions through the processes gamma q-> gamma q where q=u,d,c,s,b, anti-u, anti-d, anti-c, anti-s, anti-b. These processes have been treated in a photon-proton collision via the main reaction pp-> p gamma p-> p gamma qX at the LHC. We have employed equivalent photon approximation for incoming photon beams and performed statistical analysis for various forward detector acceptances.Comment: 17 pages, 5 figure