COMMITMENTS AND CAPABILITIES: THE ROYAL NAVY IN THE 21ST CENTURY

The size of the British Royal Navy (RN) has decreased significantly over the last century. Recent policy documents have outlined plans for new warship construction as well as an increase in maritime strategic commitments, raising the question of whether the RN’s means are sufficient to achieve the government’s desired ends. This work compares the current and future capabilities of the Royal Navy against Britain’s renewed global ambitions, to determine if the new policy is over-ambitious. It also identifies possible pitfalls that the RN may encounter as it reorients itself over the next decade. The three main findings can be summarized as follows: (1) the RN can meet its current and future commitments if the stated force structure plans are followed; (2) there is significant strategic risk associated with failure to follow-through on these plans, and finally (3) close cooperation with Britain’s allies (both in NATO and globally) will continue to be an important supporting element of RN policy. This thesis recommends expanding new frigate construction following completion of the current contracts, ensuring renewed naval diplomacy produces meaningful benefits to offset its political and economic costs, and continuing the RN’s strong track record of close integration with allies worldwide.Lieutenant, United States NavyApproved for public release. Distribution is unlimited

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Prospective Multicenter Study of Surgical Correction of Pectus Excavatum: Design, Perioperative Complications, Pain, and Baseline Pulmonary Function Facilitated by Internet-Based Data Collection

Background: Given widespread adoption of the Nuss procedure, prospective multicenter study of management of pectus excavatum by both the open and Nuss procedures was thought desirable. Although surgical repair has been performed for more than 50 years, there are no prospective multicenter studies of its management. Study Design: This observational study followed pectus excavatum patients treated surgically at 11 centers in North America, according to the method of choice of the patient and surgeon. Before operation, all underwent evaluation with CT scan, pulmonary function tests, and body image survey. Data were collected about associated conditions, hospital complications, and perioperative pain. One year after completion of treatment, patients will repeat the preoperative evaluations. This article addresses early results only. Results: Of 416 patients screened, 327 were enrolled; 284 underwent the Nuss procedure and 43 had the open procedure. Median preoperative CT index was 4.4. Pulmonary function testing before operation showed mean forced vital capacity of 90% of predicted values; forced expiratory volume in 1 second (FEV1), 89% of predicted; and forced expiratory flow during the middle half of the forced vital capacity (FEF25% to 75%), 85% of predicted. Early postcorrection results showed that operations were performed without mortality and with minimal morbidity at 30 days postoperatively. Median hospital stay was 4 days. Postoperative pain was a median of 3 on a scale of 10 at time of discharge; the worst pain experienced was the same as was expected by the patients (median 8), and by 30 days after correction or operation, the median pain score was 1. Because of disproportionate enrollment and similar early complication rates, statistical comparison between operation types was limited. Conclusions: Anatomically severe pectus excavatum is associated with abnormal pulmonary function. Initial operative correction performed at a variety of centers can be completed safely. Perioperative pain is successfully managed by current techniques

Multicenter study of pectus excavatum, final report: complications, static/exercise pulmonary function, and anatomic outcomes.

BackgroundA multicenter study of pectus excavatum was described previously. This report presents our final results.Study designPatients treated surgically at 11 centers were followed prospectively. Each underwent a preoperative evaluation with CT scan, pulmonary function tests, and body image survey. Data were collected about associated conditions, complications, and perioperative pain. One year after treatment, patients underwent repeat chest CT scan, pulmonary function tests, and body image survey. A subset of 50 underwent exercise pulmonary function testing.ResultsOf 327 patients, 284 underwent Nuss procedure and 43 underwent open procedure without mortality. Of 182 patients with complete follow-up (56%), 18% had late complications, similarly distributed, including substernal bar displacement in 7% and wound infection in 2%. Mean initial CT scan index of 4.4 improved to 3.0 post operation (severe >3.2, normal = 2.5). Computed tomography index improved at the deepest point (xiphoid) and also upper and middle sternum. Pulmonary function tests improved (forced vital capacity from 88% to 93%, forced expiratory volume in 1 second from 87% to 90%, and total lung capacity from 94% to 100% of predicted (p < 0.001 for each). VO2 max during peak exercise increased by 10.1% (p = 0.015) and O2 pulse by 19% (p = 0.007) in 20 subjects who completed both pre- and postoperative exercise tests.ConclusionsThere is significant improvement in lung function at rest and in VO2 max and O2 pulse after surgical correction of pectus excavatum, with CT index >3.2. Operative correction significantly reduces CT index and markedly improves the shape of the entire chest, and can be performed safely in a variety of centers

Multicenter study of pectus excavatum, final report: complications, static/exercise pulmonary function, and anatomic outcomes.

BackgroundA multicenter study of pectus excavatum was described previously. This report presents our final results.Study designPatients treated surgically at 11 centers were followed prospectively. Each underwent a preoperative evaluation with CT scan, pulmonary function tests, and body image survey. Data were collected about associated conditions, complications, and perioperative pain. One year after treatment, patients underwent repeat chest CT scan, pulmonary function tests, and body image survey. A subset of 50 underwent exercise pulmonary function testing.ResultsOf 327 patients, 284 underwent Nuss procedure and 43 underwent open procedure without mortality. Of 182 patients with complete follow-up (56%), 18% had late complications, similarly distributed, including substernal bar displacement in 7% and wound infection in 2%. Mean initial CT scan index of 4.4 improved to 3.0 post operation (severe >3.2, normal = 2.5). Computed tomography index improved at the deepest point (xiphoid) and also upper and middle sternum. Pulmonary function tests improved (forced vital capacity from 88% to 93%, forced expiratory volume in 1 second from 87% to 90%, and total lung capacity from 94% to 100% of predicted (p < 0.001 for each). VO2 max during peak exercise increased by 10.1% (p = 0.015) and O2 pulse by 19% (p = 0.007) in 20 subjects who completed both pre- and postoperative exercise tests.ConclusionsThere is significant improvement in lung function at rest and in VO2 max and O2 pulse after surgical correction of pectus excavatum, with CT index >3.2. Operative correction significantly reduces CT index and markedly improves the shape of the entire chest, and can be performed safely in a variety of centers