Discovery of a Candidate Inner Oort Cloud Planetoid

We report the discovery of the minor planet (90377) Sedna, the most distant object ever seen in the solar system. Prediscovery images from 2001, 2002, and 2003 have allowed us to refine the orbit sufficiently to conclude that Sedna is on a highly eccentric orbit that permanently resides well beyond the Kuiper Belt with a semimajor axis of 480 ± 40 AU and a perihelion of 76 ± 4 AU. Such an orbit is unexpected in our current understanding of the solar system but could be the result of scattering by a yet-to-be-discovered planet, perturbation by an anomalously close stellar encounter, or formation of the solar system within a cluster of stars. In all of these cases a significant additional population is likely present, and in the two most likely cases Sedna is best considered a member of the inner Oort Cloud, which then extends to much smaller semimajor axes than previously expected. Continued discovery and orbital characterization of objects in this inner Oort Cloud will verify the genesis of this unexpected population

The 2017 Session of the Nevada Legislature and the Failure of Higher Education Reform

Executive Summary This report analyzes 11 bills introduced during the 79th Session of the Nevada Legislature that proposed to reorganize, reform, and realign various aspects of the state’s higher education system. The analysis reveals the following: Despite bipartisan support for higher education reform, nearly all of the reform bills failed, including two bills vetoed by Governor Brian Sandoval. The failure to enact meaningful reform stands in contrast to the implementation of bills appropriating more resources for higher education. Opposition to reform legislation was strongest among those most invested in legitimizing and perpetuating current arrangements. The report also considers the institutional and cultural factors that reinforce these outcomes. These factors include: The mismatch between legislative capacity and the demand for policy reform. The selective manner in which higher education officials engaged in the Legislature. Misconceptions about the components of the state’s land-grant institution and the Board of Regents’ constitutional carve out prohibiting legislative action. The report concludes with policy recommendations for the Nevada Legislature. Foremost among these are: The second passage of AJR 5, an override of the AB 407 veto, and reintroduction and passage of the failed reform bills. Separation of the governance of the two- and four-year colleges from the branches of the state university, reduction in the size of the Board of Regents, and reorganization of the administration of higher education. Developing separate funding formulas for the universities and the two- and four-year colleges, and adding funding weights for courses completed by first generation, minority, and Pell Grant eligible students. Creation of the Assembly and Senate Higher Education and Economic Development Committees to improve legislative oversight and coordination. Elevation of Great Basin College to a four-year institution and realignment of the two and four-year colleges’ service areas to facilitate regional economic integration

One Hundred Years of Quail Management in Arizona

Populations of Gambel’s (Callipepla gambelii), scaled (C. squamata), and Montezuma (Cyrtornyx montezumae) quail in Arizona have fluctuated greatly in the 100 years since statehood as have regulations governing their take. The greatest fluctuations in numbers have been annual, but there is some evidence for a long-term decline in the numbers of all species. Quail hunt success has declined significantly since 1962 according to both check station information (r2 1⁄4 0.27; P,0.0001) and hunt questionnaire data (r2 1⁄4 0.35; P,0.001). Past attempts to improve or stabilize quail populations through bag limit and season adjustments have failed to impact quail numbers. Research investigating the influence of harvest on quail numbers showed that subsequent year population sizes fluctuated independent of harvest and that hunting had little effect on population size. Thus, season lengths increased over the years with late winter hunting opportunities becoming increasingly popular after 1979. Studies comparing hunted and non-hunted areas have not been conducted since late season hunting was initiated, and are needed to convince the public that quail populations in areas closed to late season hunting remain similar to those in areas open to late season hunting. Habitat conditions have also changed, deteriorating generally but improving on certain federal lands. Quail management efforts to improve hunt success by providing rainwater catchments and other habitat manipulations have not been effective at increasing population size, and water developments for livestock have resulted in long-term range deterioration. Decreasing population sizes and quail hunt success during the last 50 years, if due to environmental changes, cannot be addressed by regulation changes

Robotics Development and Design: Optical and Computer Controls

In industry today, the use of robotic systems is growing. They can be found in many diverse applications including washing dishes, assembling automobiles and carrying explosives. With such a wide range of applications, robotic systems are a very important division of engineering. Designing such systems requires an interaction between different disciplines of engineering. In the work world, engineers are required to interrelate with other engineers of differing disciplines and backgrounds. This research was designed to implement this type of partnership and develop a project that required the knowledge of an electrical, a mechanical and a computer science engineer. Using the Motorola M68HC11 microprocessor, this system is designed as a prototype for a self-contained robot. The robot will have the ability to learn paths and be remote-controlled. With a few modifications this robot would be ready to be adapted to a desired task. This research investigates the application of this single board processor and the design process required to create a small robot with self-guidance capabilities

Full Isolation Number of Matrices: Some Extremal Results

A set of nonzero entries of a (0,1)-matrix is an isolated set if no two entries belong to the same row, no two entries belong to the same column, and no two entries belong to a submatrix of the form [1 1; 1 1]. The isolation number of a matrix is the maximum size over all isolated sets. The isolation number of a matrix is a well-known and well-used lower bound for the matrix\u27s Boolean rank. We will discuss the isolation number of the adjacency matrix of various graphs and develop some extremal results for n x n matrices with isolation number n

Association of inferior vena cava filter placement for venous thromboembolic disease and a contraindication to anticoagulation with 30-day mortality

Importance: Despite the absence of data from randomized clinical trials, professional societies recommend inferior vena cava (IVC) filters for patients with venous thromboembolic disease (VTE) and a contraindication to anticoagulation therapy. Prior observational studies of IVC filters have suggested a mortality benefit associated with IVC filter insertion but have often failed to adjust for immortal time bias, which is the time before IVC filter insertion, during which death can only occur in the control group. Objective: To determine the association of IVC filter placement with 30-day mortality after adjustment for immortal time bias. Design, Setting, and Participants: This comparative effectiveness, retrospective cohort study used a population-based sample of hospitalized patients with VTE and a contraindication to anticoagulation using the State Inpatient Database and the State Emergency Department Database, part of the Healthcare Cost and Utilization Project of the Agency for Healthcare Research and Quality, from hospitals in California (January 1, 2005, to December 31, 2011), Florida (January 1, 2005, to December 31, 2013), and New York (January 1, 2005, to December 31, 2012). Data analysis was conducted from September 15, 2015, to March 14, 2018. Exposure: Inferior vena cava filter placement. Main Outcomes and Measures: Multivariable Cox proportional hazard models were constructed with IVC filters as a time-dependent variable that adjusts for immortal time bias. The Cox model was further adjusted using the propensity score as an adjustment variable. Results: Of 126 030 patients with VTE, 61 281 (48.6%) were male and the mean (SD) age was 66.9 (16.6) years. In this cohort, 45 771 (36.3%) were treated with an IVC filter, whereas 80 259 (63.7%) did not receive a filter. In the Cox model with IVC filter status analyzed as a time-dependent variable to account for immortal time bias, IVC filter placement was associated with a significantly increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). When the propensity score was included in the Cox model, IVC filter placement remained associated with an increased hazard ratio of 30-day mortality (1.18; 95% CI, 1.13-1.22; P \u3c .001). Conclusions and Relevance: After adjustment for immortal time bias, IVC filter placement was associated with increased 30-day mortality in patients with VTE and a contraindication to anticoagulation. Randomized clinical trials are needed to determine the efficacy of IVC filter placement in patients with VTE and a contraindication to anticoagulation