Point source generation of chiral fields:measures of near- and far-field optical helicity

To consider the relationship between different measures of chirality in an optical field, the simplest case is considered: direct spontaneous emission of circularly polarized light by a point source. In the electromagnetic fields radiated from a suitably chiral source, such as a low-symmetry chiral molecule undergoing radiative decay, optical helicity is exhibited in the extent of a difference in left- and right-handed circular polarization components. There are several practical measures for quantifying the emergence of ensuing optical helicity, exhibiting different forms of dependence on the properties of the emitter and the positioning of a detector. By casting each measure in terms of an irreducible helicity density, connections and distinctions can be drawn between results expressible in either classical or quantum form

Post-Pancreatoduodenectomy Outcomes and Epidural Analgesia: A 5-Year Single Institution Experience

Introduction Optimal pain control post-pancreatoduodenectomy is a challenge. Epidural analgesia (EDA) is increasingly utilized despite inherent risks and unclear effects on outcomes. Methods All pancreatoduodenectomies (PD) performed from 1/2013-12/2017 were included. Clinical parameters were obtained from retrospective review of a prospective clinical database, the ACS NSQIP prospective institutional database and medical record review. Chi-Square/Fisher’s Exact and Independent-Samples t-Tests were used for univariable analyses; multivariable regression (MVR) was performed. Results 671 consecutive PD from a single institution were included (429 EDA, 242 non-EDA). On univariable analysis, EDA patients experienced significantly less wound disruption (0.2% vs. 2.1%), unplanned intubation (3.0% vs. 7.9%), pulmonary embolism (0.5% vs. 2.5%), mechanical-ventilation >48hrs (2.1% vs. 7.9%), septic shock (2.6% vs. 5.8%), and lower pain scores. On MVR accounting for baseline group differences (gender, hypertension, pre-operative transfusion, labs, approach, pancreatic duct size), EDA was associated with less superficial wound infections (OR 0.34; CI 0.14-0.83; P=0.017), unplanned intubations (OR 0.36; CI 0.14-0.88; P=0.024), mechanical ventilation >48 hrs (OR 0.22; CI 0.08-0.62; P=0.004), and septic shock (OR 0.39; CI 0.15-1.00; P=0.050). EDA improved pain scores post-PD days 1-3 (P<0.001). No differences were seen in cardiac or renal complications; pancreatic fistula (B+C) or delayed gastric emptying; 30/90-day mortality; length of stay, readmission, discharge destination, or unplanned reoperation. Conclusion Based on the largest single institution series published to date, our data support the use of EDA for optimization of pain control. More importantly, our data document that EDA significantly improved infectious and pulmonary complications

What on Earth have we been burning? Deciphering sedimentary records of pyrogenic carbon

Humans have interacted with fire for thousands of years, yet the utilization of fossil fuels marked the beginning of a new era. Ubiquitous in the environment, pyrogenic carbon (PyC) arises from incomplete combustion of biomass and fossil fuels, forming a continuum of condensed aromatic structures. Here we develop and evaluate 14C records for two complementary PyC molecular markers, benzene-polycarboxylic-acids (BPCAs) and polycyclic-aromatic-hydrocarbons (PAHs) preserved in aquatic sediments from a sub-urban and a remote catchment in the United States (U.S.) from mid-1700s to 1998. Results show that the majority of PyC stems from local sources and is transferred to aquatic sedimentary archives on sub-decadal to millennial time scales. Whereas a small portion stems from near-contemporaneous production and sedimentation, the majority of PyC (&lt;90%) experiences delayed transmission due to ‘pre-aging’ on millennial timescales in catchment soils prior to its ultimate deposition. BPCAs (soot) and PAHs (precursors of soot) trace fossil fuel-derived PyC. Both markers parallel historical records of the consumption of fossil fuels in U.S., yet never account for more than 19% total PyC. This study demonstrates that isotopic characterization of multiple tracers is necessary to constrain histories and inventories of PyC, and that sequestration of PyC can markedly lag its production

An Innovative Approach to Decreasing Concussions in Adolescent Female Soccer Athletes: 2370 Board #117 May 29, 9

Concussion is a public health issue, fundamental to health promotion and injury prevention. Concussions are prevalent in adolescent athletic competition, in high-collision and non-collision sports. A history of previous concussion increases risk by a factor of three, female gender increases it 1.5 to 2.5 times, and female middle-school soccer players have 22.9 times increased risk during games. Non-collision concussions (indirect) may be primed by altered movement patterns from previous injuries, disruption of cervical proprioception, or musculoskeletal pain. Assessment of dynamic balance and functional movement allows identification of poor movement patterns or control. PURPOSE: To assess a preventative movement-based warm-up routine designed to re-set aberrant afferent information from various systems (vestibular, somatic, ocular) for a cohort of high school female soccer players with prior concussions. METHODS: A retrospective cohort study of convenience consisting of 17 Virginian high school female soccer athletes ages 15 to 18 during 2013-2014 season. Three players had suffered a concussion within the last 6 to 8 months. Athletes were assessed pre-season using the Lower Quarter Y-balance test (LQ-YBT) and the Functional Movement Screen (FMS). Cohort was instructed in a general warm-up placing emphasis on normalizing movement patterns (identified via the YBT and FMS), vestibular ocular reflex, and ACL-prevention exercises, which was performed during the entire season before practices and games. RESULTS: Sixteen varsity high school female soccer athletes, ages 14 to 18 years, participated. The average FMS composite score was 15±2, with 2 athletes being below the injury risk score of 14, and another 3 scoring right at the cutoff. The difference from side to side for the composite LQ-YBT ranged from 5 - 8cm. A total of 10 athletes had differences, with 6 of the athletes had an anterior difference of ≥4cm, and 6 had a posterior difference of ≥6cm. These levels are predictive of a deficit in dynamic balance. There were no new, or repeat concussions during the soccer season. CONCLUSIONS: The finding of no new or repeat concussions, suggests that the intervention may have helped and may indicate a new injury prevention paradigm

Hematoma in the Bucco-Mandibular Space: First Case Report.

Our previous studies based on intraoral dissection of fresh cadavers revealed that the fissure and loose connective tissues deep to the mucosa between the incisivus labii inferioris muscle and buccinator muscle form the entrance of the newly discovered bucco-mandibular space. To support the clinical significance of this space, we report the finding of a hematoma within this space in an adult fresh cadaver. Such a finding lends credence to studying the bucco-mandibular space and might help better understand the spread of some infections in the oral region

New periodic variable stars coincident with ROSAT sources discovered using SuperWASP

We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables. A further 30 of these objects are previously known pre-main sequence stars, for which we detect a modulation period for the first time. Amongst the newly identified periodic variables, many appear to be close eclipsing binaries, their X-ray emission is presumably the result of RS CVn type behaviour. Others are probably BY Dra stars, pre-main sequence stars and other rapid rotators displaying enhanced coronal activity. A number of previously catalogued pulsating variables (RR Lyr stars and Cepheids) coincident with X-ray sources are also seen, but we show hat these are likely to be misclassifications. We identify four objects which are probable low mass eclipsing binary stars, based on their very red colour and light curve morphology