Anthropogenic extinctions conceal widespread evolution of flightlessness in birds.

Human-driven extinctions can affect our understanding of evolution, through the nonrandom loss of certain types of species. Here, we explore how knowledge of a major evolutionary transition-the evolution of flightlessness in birds-is biased by anthropogenic extinctions. Adding data on 581 known anthropogenic extinctions to the extant global avifauna increases the number of species by 5%, but quadruples the number of flightless species. The evolution of flightlessness in birds is a widespread phenomenon, occurring in more than half of bird orders and evolving independently at least 150 times. Thus, we estimate that this evolutionary transition occurred at a rate four times higher than it would appear based solely on extant species. Our analysis of preanthropogenic avian diversity shows how anthropogenic effects can conceal the frequency of major evolutionary transitions in life forms and highlights the fact that macroevolutionary studies with only small amounts of missing data can still be highly biased.

Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial.

Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth's past interglacial warm periods1-3. About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater2 and sea level was 6 to 13 metres higher1,3. Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet3, which has been argued to have remained stable for millions of years before and includes MIS114,5. Here we show how the evolution of 234U enrichment within the subglacial waters of East Antarctica recorded the ice sheet's response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of 234U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of 234U enrichment place the inception of this reservoir at MIS11. Informed by the 234U cycling observed in the Laurentide Ice Sheet, where 234U accumulated during periods of ice stability6 and was flushed to global oceans in response to deglaciation7, we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The 234U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines8-10, indicating11 that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts10 and bacteria12 implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres13 to global sea levels.

First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA.

The NOvA experiment has seen a 4.4σ signal of ν[over ¯]_{e} appearance in a 2 GeV ν[over ¯]_{µ} beam at a distance of 810 km. Using 12.33×10^{20} protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ν[over ¯]_{µ}→ν[over ¯]_{e} candidates with a background of 10.3 and 102 ν[over ¯]_{µ}→ν[over ¯]_{µ} candidates. This new antineutrino data are combined with neutrino data to measure the parameters |Δm_{32}^{2}|=2.48_{-0.06}^{+0.11}×10^{-3} eV^{2}/c^{4} and sin^{2}θ_{23} in the ranges from (0.53-0.60) and (0.45-0.48) in the normal neutrino mass hierarchy. The data exclude most values near δ_{CP}=π/2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ_{23} values in the upper octant by 1.6σ.

Results of flap reconstruction: categorisation to reflect outcomes and process in the management of head and neck defects.

The reporting of the outcomes of flap reconstruction is often based on numerical success rates. Whilst this remains a useful variable with which to measure success, it is limited in its ability to reflect the complex processes involved. The lack of consistency in the categorisation of outcomes of flap reconstruction in the head and neck could potentially lead us to lose the opportunity to fully capture the implications of its success or failure, or both. We propose a classification that moves away from primarily reporting the results of its binary nature, and focuses more on the process of reconstruction, particularly in the head and neck.

Plasma levels of soluble membrane attack complex are elevated despite viral suppression in HIV patients with poor immune reconstitution.

The complement system is now a therapeutic target for the management of serious and life-threatening conditions such as paroxysmal nocturnal hemoglobinuria, atypical hemolytic uremic syndrome, glomerulonephritis and other diseases caused by complement deficiencies or genetic variants. As complement therapeutics expand into more clinical conditions, monitoring complement activation is increasingly important, as is the baseline levels of complement activation fragments in blood or other body fluid levels. Although baseline complement levels have been reported in the literature, the majority of these data were generated using non-standard assays and with variable sample handling, potentially skewing results. In this study, we examined the plasma and serum levels of the soluble membrane attack complex of complement (sMAC). sMAC is formed in the fluid phase when complement is activated through the terminal pathway. It binds the regulatory proteins vitronectin and/or clusterin and cannot insert into cell membranes, and can serve as a soluble diagnostic marker in infectious disease settings, as previously shown for intraventricular shunt infections. Here we show that in healthy adults, serum sMAC levels were significantly higher than those in plasma, that plasma sMAC levels were similar between in African Americans and Caucasians and that plasma sMAC levels increase with age. Plasma sMAC levels were significantly higher in virally suppressed people living with HIV (PLWH) compared to non-HIV infected healthy donors. More specifically, PLWH with CD4+ T cell counts below 200 had even greater sMAC levels, suggesting diagnostic value in monitoring sMAC levels in this group.

A spectrometer for ultrashort gamma-ray pulses with photon energies greater than 10 MeV.

We present a design for a pixelated scintillator based gamma-ray spectrometer for non-linear inverse Compton scattering experiments. By colliding a laser wakefield accelerated electron beam with a tightly focused, intense laser pulse, gamma-ray photons up to 100 MeV energies and with few femtosecond duration may be produced. To measure the energy spectrum and angular distribution, a 33 × 47 array of cesium-iodide crystals was oriented such that the 47 crystal length axis was parallel to the gamma-ray beam and the 33 crystal length axis was oriented in the vertical direction. Using an iterative deconvolution method similar to the YOGI code, modeling of the scintillator response using GEANT4 and fitting to a quantum Monte Carlo calculated photon spectrum, we are able to extract the gamma ray spectra generated by the inverse Compton interaction.

Constraints on Oscillation Parameters from ν_{e} Appearance and ν_{µ} Disappearance in NOvA.

Results are reported from an improved measurement of ν_{µ}→ν_{e} transitions by the NOvA experiment. Using an exposure equivalent to 6.05×10^{20} protons on target, 33 ν_{e} candidates are observed with a background of 8.2±0.8 (syst.). Combined with the latest NOvA ν_{µ} disappearance data and external constraints from reactor experiments on sin^{2}2θ_{13}, the hypothesis of inverted mass hierarchy with θ_{23} in the lower octant is disfavored at greater than 93% C.L. for all values of δ_{CP}.

Measurement of the Neutrino Mixing Angle θ_{23} in NOvA.

This Letter reports new results on muon neutrino disappearance from NOvA, using a 14 kton detector equivalent exposure of 6.05×10^{20} protons on target from the NuMI beam at the Fermi National Accelerator Laboratory. The measurement probes the muon-tau symmetry hypothesis that requires maximal θ_{23} mixing (θ_{23}=π/4). Assuming the normal mass hierarchy, we find Δm_{32}^{2}=(2.67±0.11)×10^{-3} eV^{2} and sin^{2}θ_{23} at the two statistically degenerate values 0.404_{-0.022}^{+0.030} and 0.624_{-0.030}^{+0.022}, both at the 68% confidence level. Our data disfavor the maximal mixing scenario with 2.6σ significance.

Management of lateral skull base cancer: United Kingdom National Multidisciplinary Guidelines.

This is the official guideline endorsed by the specialty associations involved in the care of head and neck cancer patients in the UK. It provides recommendations on the work up and management of lateral skull base cancer based on the existing evidence base for this rare condition. Recommendations • All patients with more than one of: chronic otalgia, bloody otorrhoea, bleeding, mass, facial swelling or palsy should be biopsied. (R) • Magnetic resonance and computed tomography imaging should be performed. (R) • Patients should undergo audiological assessment. (R) • Carotid angiography is recommended in select patients. (G) • The modified Pittsburg T-staging system is recommended. (G) • The minimum operation for cancer involving the temporal bone is a lateral temporal bone resection. (R) • Facial nerve rehabilitation should be initiated at primary surgery. (G) • Anterolateral thigh free flap is the workhorse flap for lateral skull base defect reconstruction. (G) • For patients undergoing surgery for squamous cell carcinoma, at least a superficial parotidectomy and selective neck dissection should be carried out. (R).

First Measurement of Electron Neutrino Appearance in NOvA.

We report results from the first search for ν_{µ}→ν_{e} transitions by the NOvA experiment. In an exposure equivalent to 2.74×10^{20} protons on target in the upgraded NuMI beam at Fermilab, we observe 6 events in the Far Detector, compared to a background expectation of 0.99±0.11(syst) events based on the Near Detector measurement. A secondary analysis observes 11 events with a background of 1.07±0.14(syst). The 3.3σ excess of events observed in the primary analysis disfavors 0.1π<δ_{CP}<0.5π in the inverted mass hierarchy at the 90% C.L.

Quantum radiation reaction in laser-electron-beam collisions.

It is possible using current high-intensity laser facilities to reach the quantum radiation reaction regime for energetic electrons. An experiment using a wakefield accelerator to drive GeV electrons into a counterpropagating laser pulse would demonstrate the increase in the yield of high-energy photons caused by the stochastic nature of quantum synchrotron emission: we show that a beam of 10(9) 1 GeV electrons colliding with a 30 fs laser pulse of intensity 10(22) W cm(-2) will emit 6300 photons with energy greater than 700 MeV, 60× the number predicted by classical theory.

Strengthening the argument for rapid brain MR imaging: estimation of reduction in lifetime attributable risk of developing fatal cancer in children with shunted hydrocephalus by instituting a rapid brain MR imaging protocol in lieu of Head CT.

BACKGROUND AND PURPOSE: Children with shunted hydrocephalus have been undergoing surveillance neuroimaging, generally in the form of head CT, for evaluation of ventricular size. As the life expectancy of these children has improved due to better shunt technology and medical care, risks related to the ionizing radiation incurred during multiple head CT examinations that they are expected to undergo throughout their lifetime have become a concern. The purpose of this study is to estimate the LAR of developing fatal cancer due to head CT for ventricular size assessment in children with shunted hydrocephalus and to assess the impact of instituting a rapid brain MR imaging protocol in reducing radiation exposure. MATERIALS AND METHODS: Retrospective review of medical records yielded 182 patients who underwent neuroimaging for assessment of ventricular size. Available neuroimaging studies (head CT and rapid brain MR) were counted and annual neuroimaging frequency was calculated. It was assumed that these patients undergo a similar number of neuroimaging studies annually through 20 years of age. A risk estimate was calculated based on the BEIR VII report and effective doses obtained using the International Commission on Radiologic Protection Report 103 organ weighting factors. RESULTS: The mean annual neuroimaging study frequency was 2.1. Based on the average age of 1.89 years, it was assumed neuroimaging surveillance commences in the second year of life. LAR was calculated assuming that a patient undergoes neuroimaging in the form of head CT at this frequency (2/year) through 20 years of age. Assuming 2 scans are performed per year and the low-dose head CT protocol is used, approximately 1 excess lifetime fatal cancer would be generated per 230 patients; with standard head CT, there would be 1 excess lifetime fatal cancer per 97 patients. CONCLUSIONS: Children with shunted hydrocephalus are at increased risk of developing fatal cancer if they are to undergo surveillance using head CT. Implementation of a rapid brain MR imaging protocol with no radiation detriment will reduce this risk.

Outcomes following pharyngolaryngectomy reconstruction with the anterolateral thigh (ALT) free flap.

We retrospectively reviewed 15 cases of pharyngolaryngectomy for advanced laryngeal carcinoma reconstructed with the anterolateral thigh (ALT) free flap. Thirteen patients had primary surgery and adjuvant treatment (radiotherapy or chemoradiotherapy), and two had salvage surgery. Thirteen had stage III or IV disease, and eight had cervical nodal extracapsular spread. In this series all the flaps survived, and at median follow-up of 14.5 months (range 3.7-31.2), 12 of the 15 patients were alive. One patient developed a chronic pharyngocutaneous fistula, and five required repeat balloon dilatations for late pharyngeal strictures. Six patients enjoyed restoration of full oral intake, seven were able to take a soft diet, and two were dependent on feeding by percutaneous endoscopic gastrostomy. Four patients developed adequate tracheo-oesophageal speech, and one successfully developed oesophageal speech. In this series many of the surgical problems associated with pharyngolaryngectomy reconstruction were addressed successfully by the ALT, but late dysphagia remained troublesome in an appreciable minority. While adjuvant radiotherapy could have contributed to this, future innovations will focus on the reduction of late strictures.

Walking speed adaptation ability of Myzus persicae to different temperature conditions.

Walking speeds were calculated for nine clones of the peach potato aphid Myzus persicae collected from three countries along a latitudinal cline of its European distribution from Sweden to Spain (Sweden, UK and Spain), and the effects of collection origin and intra and intergenerational acclimation were investigated. Walking speeds declined with decreasing temperature, with maximum performance at temperatures closest to acclimation temperature (fastest median walking speed of 5.8 cm min(-1) was recorded for clone UK 3, collected from the UK, at 25°C after acclimating to 25°C for one generation). Following acclimation at both 20°C and 25°C, walking ceased (as indicated by median walking speeds of 0.0 cm min(-1)) at temperatures as high as 7.5°C and 12.5°C. However, acclimation at 10°C enabled mobility to occur to temperatures as low as 0°C. There was no relationship between mobility and latitude of collection, suggesting that large scale mixing of aphids may occur across Europe. However, clonal variation was suggested, with clone UK 3 outperforming the majority of other clones across all temperatures at which mobility was maintained following acclimation at 10°C for one and three generations and at 25°C for one generation. The Scandinavian clones consistently outperformed their temperate and Mediterranean counterparts at the majority of temperatures following acclimation for three generations at 25°C.

Safety of a regimen for thromboprophylaxis in head and neck cancer microvascular reconstructive surgery: non-concurrent cohort study.

We aimed to assess bleeding complications after increasing the thromboprophylactic dose of dalteparin from 2500 to 5000 units 12h preoperatively in line with guidance on risk stratification and appropriate pharmacological thromboprophylaxis. We evaluated two groups of patients for confounding factors and bleeding, a prospective consecutive high dose group (n=29), and a retrospective low dose group (n=30) who had had ablative and microvascular reconstructive surgery for oral or oropharyngeal cancer. The bleeding index over 5 days (range 40-60) was used as an objective measure of perioperative bleeding. The null hypothesis was that there was no difference in the bleeding index between the two groups. We found no significant difference in the mean bleeding index between the two groups (p=0.56) (mean (SD) bleeding index in the high dose group 45.3 (26.1), and 48.7 (18.1) in the low dose group). The 95% confidence interval (CI) was -1.51 lower to 0.83 higher in the high dose group. Five patients (2 (7%) in the high dose, and 3 (10%) in the low dose group) were returned to theatre with bleeding complications. There was a trend to a higher failure rate of free flaps in the high dose group (4 (13%) complete, and 1 partial failure compared with 1 (3%) complete and 1 partial failure in the low dose group). There were no symptomatic thromboembolic events in either group. An increased dose of dalteparin did not seem to increase conventional surgical bleeding complications, which was consistent with the null hypothesis at evidence level 2b, but a larger sample is needed to explore its impact on venous thromboembolic events and on the failure of microvascular free flaps.

SU-E-I-10: Putting Teeth into Your CT Dosimetry Program: Approaches to Cone- Beam Dental/Maxillofacial CT Dosimetry.

PURPOSE: To review and compare different approaches to the problem of dosimetry for limited field-of-view (FOV) cone beam CT devices for dental and maxillofacial applications. METHODS: The determination of patient doses from specialized, cone-beam CT devices for dental and maxillofacial work requires medical physicists to re-evaluate their dosimetry methods. These devices work in cone-beam geometry, with an axial field dimension on the order of the lengths of the standard head CTDI phantom and pencil ionization chamber. They may also utilize less than 360 degree scans, resulting in asymmetrical radiation distributions. This operating regime is far from that for which conventional CT dosimetry was designed, and alternative approaches must be considered. The alternatives include extensions of conventional CT dosimetry currently used for large axial FOV scanners (e.g. the extended CTDI parameter (CTDIe) for the Toshiba Aquillion One with 160 mm axial FOV) and the new method based on point dosimetry measurements recently formalized in AAPM Report TG-111. Conventional, modified-conventional, and TG-111 dosimetry measurements are used in two CT dose phantoms (adult head and pediatric head) to obtain dose indices for the Planmeca ProMax 3D Max dental CT scanner. Surface dose maps are generated using radiochromic film for correlation with the chamber dosimetry. RESULTS: Results for the three dosimetry approaches are compared for the specific case of the ProMax 3D Max scanner. Strengths and weaknesses of the three measurement paradigms for this type of application are compared. CONCLUSIONS: The increasing availability of specialized scanners operating in full cone-beam mode will require the clinical medical physicist to be conversant with extensions to the CT dose index methodology suitable for this equipment.

SU-E-I-57: CT Dose Metrics: What Are We Tracking.

PURPOSE: Recent guidance by The Joint Commission and CRCPD recommendations require establishing CT reference dose levels (RDLs) for clinical protocols and recording CT dose metrics in the patient's medical record. This presentation addresses which dose values in the CT report should be recorded for the purposes of monitoring patient dose and determining RDLs effectively. METHODS: CT dose reports are commonly recorded in the PACS as screen captures, although structured reporting is becoming available on current CT scanners and PACS systems. The goal is to obtain data that correctly reflects the patient's dose, but the dose information captured is not standardized across vendors and can be difficult to compare. Multi-phase studies, deviations from established protocols and dynamic scanning present problems when recording numbers to establish RDLs because of the lack of information on the anatomy scanned. The cumulative DLP and CTDIvol manually entered by radiologic technologists into the electronic medical record were compared with more detailed dose metrics compiled from PACS images. RESULTS: Analysis of this data showed that simple cumulative metrics are a poor indicator of patient dose. Major problems are 1) the inclusion of dynamic scan doses associated with bolus tracking, which can skew protocol CTDIvol values by a factor of up to 20, and 2) add-on scans of non-overlapping anatomy which can inaccurately increase apparent patient dose. CONCLUSIONS: Recording CTDIvol to monitor patient doses is not straightforward, since details of the actual anatomy scanned are lacking without image-based review. More granular dose reporting which identifies individual acquisitions is required; however, current RIS systems do not provide the flexibility necessary to capture all this information.