Optimum design of high speed prop rotors including the coupling of performance, aeroelastic stability and structures

An optimization procedure is developed for the design of high speed prop-rotors to be used in civil tiltrotor applications. The goal is to couple aerodynamic performance, aeroelastic stability, and structural design requirements inside a closed-loop optimization procedure. The objective is to minimize the gross weight and maximize the propulsive efficiency in high speed cruise. Constraints are imposed on the rotor aeroelastic stability in both hover and cruise and rotor figure of merit in hover. Both structural and aerodynamic design variables are used

Male spotted bowerbirds propagate fruit for use in their sexual display

Cultivation may be described as a process of co-evolution and niche construction, with two species developing a mutualistic relationship through association, leading to coordinated change [1]. Cultivation is rare but taxonomically widespread, benefiting the cultivator, usually through increased access to food, and the cultivar, by improved growth and protection, driving co-evolutionary changes (Supplemental information). Humans cultivate more than food, producing clothing, construction materials, fuel, drugs, and ornaments. A population of male spotted bowerbirds Ptilonorhynchus (Chlamydera) maculata uses fruits of Solanum ellipticum (Figure 1A), not as food but as important components of their sexual display [2,3]. Here, we show that males indirectly cultivate plants bearing these fruit - the first example of cultivation of a non-food item by a species other than humans. Plants appear at bowers following male occupation (Figure 1B). Males benefit, exhibiting more fruit at their bowers. Plants benefit because fruit are deposited in better germination sites. Fruits from plants near bowers differ visually from those far from bowers, and look more similar to fruits that are preferred by males in choice tests

Model-Informed Risk Assessment and Decision Making for an Emerging Infectious Disease in the Asia-Pacific Region

Background: Effective response to emerging infectious disease (EID) threats relies on health care systems that can detect and contain localised outbreaks before they reach a national or international scale. The Asia-Pacific region contains low and middle income countries in which the risk of EID outbreaks is elevated and whose health care systems may require international support to effectively detect and respond to such events. The absence of comprehensive data on populations, health care systems and disease characteristics in this region makes risk assessment and decisions about the provision of such support challenging.\ud \ud Methodology/principal findings: We describe a mathematical modelling framework that can inform this process by integrating available data sources, systematically explore the effects of uncertainty, and provide estimates of outbreak risk under a range of intervention scenarios. We illustrate the use of this framework in the context of a potential importation of Ebola Virus Disease into the Asia-Pacific region. Results suggest that, across a wide range of plausible scenarios, preemptive interventions supporting the timely detection of early cases provide substantially greater reductions in the probability of large outbreaks than interventions that support health care system capacity after an outbreak has commenced.\ud \ud Conclusions/significance: Our study demonstrates how, in the presence of substantial uncertainty about health care system infrastructure and other relevant aspects of disease control, mathematical models can be used to assess the constraints that limited resources place upon the ability of local health care systems to detect and respond to EID outbreaks in a timely and effective fashion. Our framework can help evaluate the relative impact of these constraints to identify resourcing priorities for health care system support, in order to inform principled and quantifiable decision making

Multi-robot System Based on Model of Wolf Hunting Behavior to Emulate Wolf and Elk Interactions

Wolves are one of the most successful large predators on earth. Their success is made apparent by their presence in most northern ecosystems. They owe much of this success to their generalized hunting behavior which allows them to quickly and effectively adjust to different species of prey. The success of this hunting behavior for wolves is the inspiration for a project to bestow this behavior onto a system of robots with the hopes that they might utilize the apparent strengths of the behavior to achieve their own success

Cryptosporidium, Enterocytozoon, and Cyclospora Infections in Pediatric and Adult Patients with Diarrhea in Tanzania.

Cryptosporidiosis, microsporidiosis, and cyclosporiasis were studied in four groups of Tanzanian inpatients: adults with AIDS-associated diarrhea, children with chronic diarrhea (of whom 23 of 59 were positive [+] for human immunodeficiency virus [HIV]), children with acute diarrhea (of whom 15 of 55 were HIV+), and HIV control children without diarrhea. Cryptosporidium was identified in specimens from 6/86 adults, 5/59 children with chronic diarrhea (3/5, HIV+), 7/55 children with acute diarrhea (0/7, HIV+), and 0/20 control children. Among children with acute diarrhea, 7/7 with cryptosporidiosis were malnourished, compared with 10/48 without cryptosporidiosis (P < .01). Enterocytozoon was identified in specimens from 3/86 adults, 2/59 children with chronic diarrhea (1 HIV+), 0/55 children with acute diarrhea, and 4/20 control children. All four controls were underweight (P < .01). Cyclospora was identified in specimens from one adult and one child with acute diarrhea (HIV-). Thus, Cryptosporidium was the most frequent and Cyclospora the least frequent pathogen identified. Cryptosporidium and Enterocytozoon were associated with malnutrition. Asymptomatic fecal shedding of Enterocytozoon in otherwise healthy, HIV children has not been described previously

The Effects of Federal Inter-Regional Transfers with Optimizing Regional Governments

This paper analyses a simple inter-governmental transfer within a two-regional federal model with optimising regional governments and an exogenous federal government. Regions are linked by inter-regional migration of labour and households migrate from one region to the other in response to inter-regional differences in utility. Regional governments determined their tax and expenditure settings in order to maximise the welfare of the region's representative household. The federal government exists solely to transfer resources from one region to another. The model is solved numerically, after linearlisation and calibration using data for the Australian states. We find that the federal government transfers have only trivial effects on welfare, ie that the welfare effects of the transfer are undone by the migration response of households and the tax and expenditure changes of regional governments. Most of the 'undoing' comes from inter-regional migration.

Competitive Federalism: A Political-Economy General Equilibrium Approach

This paper develops a modelling framework within which questions of fiscal federalism can be handled. Regional computable general equilibrium (CGE) models form one good approach for examining such questions. However, conventional regional CGE models contain little, if any, theory relating to optimal economic decision-making by governments. In this paper we overcome this limitation by analysing a simple two-region GE model to which maximising behaviour by regional governments is added. We call this a regional political-economy general equilibrium (PEGE) model. We begin by considering a model with only regional governments. We then introduce a rudimentary federal government and consider two cases; in the first the federal government carries out a lump-sum transfer of resources from one regional government to another and in the second it imposes lump-sum income taxes on households and uses this revenue to make transfers to regional governments. We compare the implications of the PEGE model with and without the federal government transfers and conclude that optimising regional governments change their own tax rates to offset the effects on their citizens of the federal government action.