Degeneracy between mass and spin in black-hole-binary waveforms

We explore the degeneracy between mass and spin in gravitational waveforms emitted by black-hole binary coalescences. We focus on spin-aligned waveforms and obtain our results using phenomenological models that were tuned to numerical-relativity simulations. A degeneracy is known for low-mass binaries (particularly neutron-star binaries), where gravitational-wave detectors are sensitive to only the inspiral phase, and the waveform can be modelled by post-Newtonian theory. Here, we consider black-hole binaries, where detectors will also be sensitive to the merger and ringdown, and demonstrate that the degeneracy persists across a broad mass range. At low masses, the degeneracy is between mass ratio and total spin, with chirp mass accurately determined. At higher masses, the degeneracy persists but is not so clearly characterised by constant chirp mass as the merger and ringdown become more significant. We consider the importance of this degeneracy both for performing searches (including searches where only non-spinning templates are used) and in parameter extraction from observed systems. We compare observational capabilities between the early (~2015) and final (2018 onwards) versions of the Advanced LIGO detector.Comment: 11 pages, 9 figure

Virginia Beach Middle School Technology Education Teachers Reinforcing Academic Standards

The following objectives were established to address this problem: 1. Determine Virginia Beach Middle School Technology Education teachers involvement in assisting students to master Virginia Standards of Learning competencies; 2. Determine the types of assistance that the Virginia Beach Public School system provides to help align the SOL of the academic curriculum with instruction in the curriculum of Technology Education; 3. Determine specific means that teachers have used to integrate the academic curriculum with instruction in the Technology Education curriculum

Ethical Purchasing And Selling By DCs

Dr Perle's article on ethics in purchasing for chiropractic treatment.http://www.dynamicchiropractic.com/mpacms/dc/article.php?id=5428

Portal vein thrombosis after laparoscopic splenectomy: an ongoing clinical challenge.

ObjectivesPortal vein thrombosis (PVT) following open splenectomy is a potentially lethal complication with an incidence of up to 6%. The objective of this report is to describe our management of a recent laparoscopic case, discuss current therapies, and consider antiplatelet therapy for prophylaxis.MethodsMedical records, laboratory studies, and imaging studies pertaining to a recent case of a laparoscopic splenectomy were examined. Current literature related to this topic was reviewed.ResultsA 16-year-old girl underwent laparoscopic splenectomy for idiopathic thrombocytopenic purpura. Her preoperative platelet count was 96K. She was discharged on postoperative day 1 after an uneventful operation including division of the splenic hilum with an endoscopic linear stapler. On postoperative day 20, she presented with a 5-day history of epigastric pain, nausea, and low-grade fevers without peritoneal signs. Her white blood cell count was 17.3; her platelets were 476K. Computed tomography demonstrated thrombosis of the splenic, superior mesenteric, and portal veins propagating into the liver. Heparinization was begun followed by an unsuccessful attempt at pharmacologic and mechanical thrombolysis by interventional radiology. Over the next 5 days, her pain resolved, she tolerated a full diet, was converted to oral anticoagulation and sent home. Follow-up radiographic studies demonstrated the development of venous collaterals and cavernous transformation of the portal vein.DiscussionNo standard therapy for PVT exists; several approaches have been described. These include systemic anticoagulation, systemic or regional medical thrombolysis, mechanical thrombolysis, and surgical thrombectomy. Unanswered questions exist about the most effective acute therapy, duration of anticoagulation, and the potential efficacy of routine prophylaxis with perioperative antiplatelet agents. PVT following splenectomy occurs with both the open and laparoscopic approach

Building research capacity in Education: evidence from recent initiatives in England, Scotland and Wales.

There is a pressing need to build research capacity in Education across the UK to combat the effects of the ageing research population and the increasing polarisation between research-intensive institutions and the remainder of the field. This paper draws data from three evaluations of recent initiatives across the UK to explore the necessary conditions for effectively building research capacity. Technicist and situated learning models are explored in relation to the immediate and longer term professional development of the research workforce, and we identify that central to the effectiveness of this professional learning is: (1) interpersonal support from more experienced colleagues; and (2) institutional support for research engagement, primarily in the provision of time and an infrastructure which can support research activity. We conclude that the development of, and engagement with, inter-institutional, inter-project communities is imperative to this process

Sampling the Porridge: A Comparison of Ordered Variable Regression with \u3cem\u3eF\u3c/em\u3e and \u3cem\u3eR\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e and Multiple Linear Regression with Corrected \u3cem\u3eF\u3c/em\u3e and \u3cem\u3eR\u3c/em\u3e\u3csup\u3e2\u3c/sup\u3e in the Presence of Multicollinearity

Differences between the multiple linear regression model with Corrected R2 and Corrected F and the ordered variable regression model with R2 and F when intercorrelation is present are illustrated with simulated and real-world data