Constrained Differential Optimization

Many optimization models of neural networks need constraints to restrict the space of outputs to a subspace which satisfies external criteria. Optimizations using energy methods yield "forces" which act upon the state of the neural network. The penalty method, in which quadratic energy constraints are added to an existing optimization energy, has become popular recently, but is not guaranteed to satisfy the constraint conditions when there are other forces on the neural model or when there are multiple constraints. In this paper, we present the basic differential multiplier method (BDMM), which satisfies constraints exactly; we create forces which gradually apply the constraints over time, using "neurons" that estimate Lagrange multipliers. The basic differential multiplier method is a differential version of the method of multipliers from Numerical Analysis. We prove that the differential equations locally converge to a constrained minimum. Examples of applications of the differential method of multipliers include enforcing permutation codewords in the analog decoding problem and enforcing valid tours in the traveling salesman problem

Alternative, Grassroots, And Rogue Leadership: A Case For Alternating Leaders In Organizations

The article examines traditional understanding of top-down organizational leadership against spontaneous, self-initiated leadership/followership theory. It also denotes the relationship between spontaneous and self-initiated expression of alternative, grassroots, and rogue leadership as a construct of alternating leadership behaviors. The research furthers the leadership research focus that is identified as Alternating Leadership and acknowledges leader/follower dual function within each individual. The constructs are augmented by a matrix that contrasts the strength of the leadership and followership roles among traditional versus non-traditional leadership theories. Conclusions suggest a confirmation of the dual Alternating Leadership role existing within all employees or managers and the creation of worker-centered, real-time interventions to increase employee interaction and synergy. The impact of generational leadership on the Alternating Leadership Model is also examined

Sequential Simulation (SqS): an empirical and theoretical model

Ethics statement: The authors declare that they have followed the guidelines for scientific integrity and professional ethics. The article does not contain any studies with human or animal subjects. Introduction & Aim: Stroke is one of the leading causes of morbidity and mortality worldwide. In eligible patients with acute ischemic stroke, early treatment with intravenous thrombolysis is crucial for a good patient outcome. We introduced simulation training sessions in conjunction with an improved treatment protocol as part of a quality improvement project to reduce door-to-needle times in stroke thrombolysis. Methods: A questionnaire assessing our preexisting treatment protocol was sent to all members of the stroke team. A panel of experts reviewed the responses and suggested potential changes to streamline the treatment protocol. In February 2017, we introduced the new protocol along with weekly videotaped in-situ scenario based simulation sessions with all stroke team members as participants. Previous stroke patients acted as markers. Kirkpatrick’s four-level training evaluation model was used for assessment. Here we present 1) Participant reactions (level 1) on a Likert item from 0-10, and 2) Median door-to-needle times in stroke thrombolysis, a measure of clinical behavioral change (level 3), using a statistical process control method. Simulated performance and long term patient outcomes will be assessed in future analysis. Results & Discussion: Participant reactions were predominantly positive. Self-perceived learning scored a median of 8 (IQR 7-9). We compared door-to-needle times for 478 prospectively included patients with acute ischemic stroke treated with intravenous thrombolysis at our hospital from January 2014 – July 2017. There was a significant reduction in median door-to-needle time from 27 (IQR 19-41) to 13 minutes (IQR 9-21, p<0.001) for the 78 patients in the post-intervention group. The results remained significant regardless of time of admission. There were no significant changes in the rate of stroke mimics, prehospital time or fatal intracranial hemorrhage. Simulation training in conjunction with protocol improvement led to an immediate and significant reduction of median door-to-needle time in stroke thrombolysis (Fig. 1). To our knowledge, no other published data have shown lower median treatment times. Combining simulation training with protocol change holds promise as a method both for effective implementation and significant results in attempts to reduce in-hospital delays in stroke thrombolysis. Effects on non-technical skills, provider variability and long term patient outcomes are yet to be evaluated

Effects of the Simulation Using Team Deliberate Practice (Sim-TDP) model on the performance of undergraduate nursing students

Background The use of simulation has grown in prominence, but variation in the quality of provision has been reported, leading to calls for further research into the most effective instructional designs. Simulation Using Team Deliberate Practice (Sim-TDP) was developed in response. It combines the principles of simulation with deliberate practice, therefore, providing participants with opportunities to work towards well-defined goals, rehearse skills and reflect on performance whilst receiving expert feedback. This study aimed to compare the effects of Sim-TDP, versus the use of traditional simulation, on the performance of second year adult nursing students. Methods Using a longitudinal quasi-experimental design, the effects of the two approaches were compared over a 1-year period. Sixteen groups, each containing an average of six participants, were randomised into an intervention arm (n=8) or comparison arm (n=8). Data collection took place at 3 monthly intervals, at which point the performance and time to complete the scenario objectives/tasks, as a team, were recorded and analysed using a validated performance tool. Results The independent t-tests, comparing the performance of the groups, did not demonstrate any notable differences during the three phases. However, in phase 1, the independent t-tests suggested an improvement in the Sim-TDP participants’ time spent on task (t (14) = 5.12, p<0.001), with a mean difference of 7.22 min. The mixed analysis of covariance inferred that the use of the Sim-TDP led to an improvement, over time, in the participants’ performance (F(1, 5) = 12.91, p=0.016), and thus, an association between Sim-TDP and the enhanced performance of participants. Conclusion The results suggest that Sim-TDP, potentially, optimised participant performance, while maximising the use of Simulation-based education (SBE) resources, such as simulation facilities and equipment. The model could be of practical benefit to nurse educators wishing to integrate SBE into their programmes

Collapsing Stakeholder Groups: Insights Into Professional Sports Organizations And Competitive Positioning

The article investigates the force field stakeholder structure of National Football League (NFL) sport organizations relative to those that provide the domain that governs the management of other medium to large commercial entities. Textual and visual images of the affiliations among the various NFL organizations&rsquo; stakeholder groups in the manuscript provide a framework of the stakeholder force field domain. The model presents comparative and contrasting data relevant to typical business organizations of similar size, expenses, and revenue capacity. Finally, the article identifies managerial practices in NFL organizations and provides explanations for these processes applicable to the force field domain under which they are governed. The authors conclude that managerial practices in NFL organizations are contrary to those adhered to in regular commercial enterprises; however, these managerial practices are appropriate for the particular stakeholder force field domain that governs these particular sport organizations, which fosters &ldquo;collaborative parity.&rdquo; Future research that delves into areas of major league football&rsquo;s and other leagues&rsquo; evolving economic constructs as they pertain to stakeholder issues such as controlling labor costs, the relocation of a particular team, and the necessity of increasing the volume of existing and emerging revenue streams is recommended

Effects of a single interprofessional simulation session on medical and nursing students’ attitudes toward interprofessional learning and professional identity: a questionnaire study

Background Participation in simulation-based interprofessional education (sim-IPE) may affect students’ attitudes towards interprofessional learning (through gaining experience with others) and their professional identity (by increasing the ‘fit’ of group membership). We examined this in two questionnaire studies involving students from four universities in two areas of the UK. Method Questionnaire data were collected before and after students took part in a sim-IPE session consisting of three acute scenarios. Questionnaires included the Readiness for Interprofessional Learning Scale (RIPLS) and measures of professional identity derived from the social identity theory literature. In Study 1, only identification with Professional Group (doctor or nurse) was measured, while in Study 2 identification with Student Group (medical or nursing student) and the immediate interprofessional Team worked with in the simulation were also measured. Linear mixed effects regression analysis examined the effect of the simulation session, and differences between medical and nursing students, sites and identity measures. Results A total of 194 medical and 266 nursing students completed questionnaires. A five-item subset of RIPLS (RIPLSCore) was used in analysis. In both studies RIPLSCore increased for all groups following participation in sim-IPE, although this was larger for nursing students in Study 1. Nursing students had consistently higher RIPLSCore scores than medical students at one site. Effects of the session on identity varied between sites, and dimensions of identity. Notably, while positive emotions associated with group membership (Ingroup Affect) increased for Student Group, Professional Group and Team, the sense of belonging (Ingroup Ties) and importance (Centrality) of the group increased only for Team. Nursing students had consistently higher identification scores than medical students. Conclusions Participation in a sim-IPE session can improve attitudes towards interprofessional learning. It can also enhance professional identity, particularly as related to emotional aspects of group membership, with possible benefits for wellbeing. Changes in identification with the immediate Team suggest positive psychological consequences of ad hoc Team formation in the workplace. Differences between medical and nursing students suggest their differing opportunities to work with other professions during training may change baseline attitudes and identity. However, a single sim-IPE session can still have an additive effect

Mechanical design engineering. NASA/university advanced design program: Lunar Bulk Material Transport Vehicle

The design of a Lunar Bulk Material Transport Vehicle (LBMTV) is discussed. Goals set in the project include a payload of 50 cubic feet of lunar soil with a lunar of approximately 800 moon-pounds, a speed of 15 mph, and the ability to handle a grade of 20 percent. Thermal control, an articulated steering mechanism, a dump mechanism, a self-righting mechanism, viable power sources, and a probable control panel are analyzed. The thermal control system involves the use of small strip heaters to heat the housing of electronic equipment in the absence of sufficient solar radiation and multi-layer insulation during periods of intense solar radiation. The entire system uses only 10 W and weighs about 60 pounds, or 10 moon-pounds. The steering mechanism is an articulated steering joint at the center of the vehicle. It utilizes two actuators and yields a turning radius of 10.3 feet. The dump mechanism rotates the bulk material container through an angle of 100 degree using one actuator. The self-righting mechanism consists of two four bar linkages, each of which is powered by the same size actuator as the other linkages. The LBMTV is powered by rechargeable batteries. A running time of at least two hours is attained under a worst case analysis. The weight of the batteries is 100 pounds. A control panel consisting of feedback and control instruments is described. The panel includes all critical information necessary to control the vehicle remotely. The LBMTV is capable of handling many types of cargo. It is able to interface with many types of removable bulk material containers. These containers are made to interface with the three-legged walker, SKITTER. The overall vehicle is about 15 feet in length and has a weight of about 1000 pounds, or 170 lunar pounds

Lymphatic vasculature mediates macrophage reverse cholesterol transport in mice

Reverse cholesterol transport (RCT) refers to the mobilization of cholesterol on HDL particles (HDL-C) from extravascular tissues to plasma, ultimately for fecal excretion. Little is known about how HDL-C leaves peripheral tissues to reach plasma. We first used 2 models of disrupted lymphatic drainage from skin — 1 surgical and the other genetic — to quantitatively track RCT following injection of [3H]-cholesterol–loaded macrophages upstream of blocked or absent lymphatic vessels. Macrophage RCT was markedly impaired in both models, even at sites with a leaky vasculature. Inhibited RCT was downstream of cholesterol efflux from macrophages, since macrophage efflux of a fluorescent cholesterol analog (BODIPY-cholesterol) was not altered by impaired lymphatic drainage. We next addressed whether RCT was mediated by lymphatic vessels from the aortic wall by loading the aortae of donor atherosclerotic Apoe-deficient mice with [2H]6-labeled cholesterol and surgically transplanting these aortae into recipient Apoe-deficient mice that were treated with anti-VEGFR3 antibody to block lymphatic regrowth or with control antibody to allow such regrowth. [2H]-Cholesterol was retained in aortae of anti–VEGFR3-treated mice. Thus, the lymphatic vessel route is critical for RCT from multiple tissues, including the aortic wall. These results suggest that supporting lymphatic transport function may facilitate cholesterol clearance in therapies aimed at reversing atherosclerosis

How global biodiversity hotspots may go unrecognized: Lessons from the North American Coastal Plain

© 2014 John Wiley & Sons Ltd. Biodiversity hotspots are conservation priorities. We identify the North American Coastal Plain (NACP) as a global hotspot based on the classic definition, a region with \u3e 1500 endemic plant species and \u3e 70% habitat loss. This region has been bypassed in prior designations due to misconceptions and myths about its ecology and history. These fallacies include: (1) young age of the NACP, climatic instability over time and submergence during high sea-level stands; (2) climatic and environmental homogeneity; (3) closed forest as the climax vegetation; and (4) fire regimes that are mostly anthropogenic. We show that the NACP is older and more climatically stable than usually assumed, spatially heterogeneous and extremely rich in species and endemics for its range of latitude, especially within pine savannas and other mostly herbaceous and fire-dependent communities. We suspect systematic biases and misconceptions, in addition to missing information, obscure the existence of similarly biologically significant regions world-wide. Potential solutions to this problem include (1) increased field biological surveys and taxonomic determinations, especially within grassy biomes and regions with low soil fertility, which tend to have much overlooked biodiversity; (2) more research on the climatic refugium role of hotspots, given that regions of high endemism often coincide with regions with low velocity of climate change; (3) in low-lying coastal regions, consideration of the heterogeneity in land area generated by historically fluctuating sea levels, which likely enhanced opportunities for evolution of endemic species; and (4) immediate actions to establish new protected areas and implement science-based management to restore evolutionary environmental conditions in newly recognized hotspots