Implications Of Mixed Results With Cointegration Models In International Studies

While cointegration models have been used extensively in many fields (such as in testing for stock market predictability), there have been mixed results from using cointegration models in international studies.  For example, one study attempted to regress the levels of the general stock market price indexes of Norway, Mexico, Venezuela, and of Oman on the levels of interest rate and oil prices variables during the period 1992 to 1999.  Attempts to explain mixed results have included distinguishing developed markets versus less developed markets and differences in the volatilities of markets. Another approach has been attempts to improve cointegration methods.  Some studies have included both bivariate and multivariate methods of cointegration.  Others have employed augmented Dickey-Fuller unit root tests of the residuals.  The extent of mixed results in international studies has implications for earlier studies in single countries.  It is possible that many earlier studies in business and in economics will need to be replicated using newer techniques developed by international researchers.  The purpose of this study is to explain the attempts to improve cointegration methods, the mixed results in international studies, and the implications for earlier studies relying upon cointegration models

Lunar Wireless Power Transfer Feasibility Study

This study examines the feasibility of a multi-kilowatt wireless radio frequency (RF) power system to transfer power between lunar base facilities. Initial analyses, show that wireless power transfer (WPT) systems can be more efficient and less expensive than traditional wired approaches for certain lunar and terrestrial applications. The study includes evaluations of the fundamental limitations of lunar WPT systems, the interrelationships of possible operational parameters, and a baseline design approach for a notionial system that could be used in the near future to power remote facilities at a lunar base. Our notional system includes state-of-the-art photovoltaics (PVs), high-efficiency microwave transmitters, low-mass large-aperture high-power transmit antennas, high-efficiency large-area rectenna receiving arrays, and reconfigurable DC combining circuitry

Spatial heterogeneity enhances and modulates excitability in a mathematical model of the myometrium

The muscular layer of the uterus (myometrium) undergoes profound changes in global excitability prior to parturition. Here, a mathematical model of the myocyte network is developed to investigate the hypothesis that spatial heterogeneity is essential to the transition from local to global excitation which the myometrium undergoes just prior to birth. Each myometrial smooth muscle cell is represented by an element with FitzHugh–Nagumo dynamics. The cells are coupled through resistors that represent gap junctions. Spatial heterogeneity is introduced by means of stochastic variation in coupling strengths, with parameters derived from physiological data. Numerical simulations indicate that even modest increases in the heterogeneity of the system can amplify the ability of locally applied stimuli to elicit global excitation. Moreover, in networks driven by a pacemaker cell, global oscillations of excitation are impeded in fully connected and strongly coupled networks. The ability of a locally stimulated cell or pacemaker cell to excite the network is shown to be strongly dependent on the local spatial correlation structure of the couplings. In summary, spatial heterogeneity is a key factor in enhancing and modulating global excitability

Numerical Simulation Of An Over-Expanded Supersonic Nozzle Flow

Paper presented at 2018 Canadian Society of Mechanical Engineers International Congress, 27-30 May 2018.Flaring in oil and gas production is the controlled burning of unwanted exhaust gases to enhance safety. Obtaining complete combustion and thus eliminating or reducing smoke is critical to meet increasingly strict environmental regulations. To improve flare combustion, gas flares are equipped with air nozzles that introduce extra oxygen and improve mixing in the combustion zone. These nozzles are operated in the subsonic, sonic, or supersonic regimes. In this paper we are concerned with turbulence modeling of the jet flow exiting from a particular convergent-divergent nozzle used in flare systems. The Realizable − and SST − models are used to study the compressible flow within that specific nozzle, which has an exit diameter of 3.38 mm and has convergent and divergent sections that are connected via a throat section with a finite length and constant diameter. The velocity profiles and turbulent kinetic energy predicted by both turbulence models, in the vicinity of the nozzle outlet and along the symmetry axis of the nozzle, are compared for nozzle pressure ratios in the range 1.18≤NPR ≤1.78 . It is shown that for ≤1, both turbulence models predict nearly identical flow evolution along the nozzle. When the flow becomes supersonic, the shock surface, and consequently nozzle outlet velocity profiles, predicted by the SST − model deviates slightly from the other model. The differences, however, become negligible a couple of diameters downstream of the nozzle outlet. Computed entrainment rate coefficients vary slightly when changing the turbulence model, and this difference remains insignificant with increasing downstream distance

Teacher Reform in Indonesia: The Role of Politics and Evidence in Policy Making

Teacher Reform in Indonesia: The Role of Politics and Evidence in Policy Making is the result of seven years of collaborative effort between the Human Development Sector of the World Bank Indonesia country office and the Government of Indonesia. The Human Development Sector, led by Mae Chu Chang, produced over 50 independent background papers by Bank staff, government researchers, and international consultants, as well several major research projects including an impact evaluation and in-depth classroom observations. This synthesis report was prepared under the team leadership of Mae Chu Chang and included as mem- bers Samer Al-Samarrai, Andrew Ragatz, Joppe de Ree, Sheldon Shaeffer, and Ritchie Stevenson (co-authors) as well as Rina Arlianti, Susiana Iskandar, and Titie Hadiyati (contributors). Research assistance was provided by Shahnaz Arina, Megha Kapoor, Imam Setiawan, and Susie Sugiarti. Mary Anderson provided editorial support, and the graphic designer was Yvonne Armanto Ramali. \ud The production of this report, as well as the variety of research studies con- ducted over the past seven years on which the book is based, was generously supported by the Dutch Education Support Program (DESP) funded by the Government of the Kingdom of the Netherlands. The team is indebted to Arnold Vander Zanden (First Secretary Education, Royal Netherlands Embassy, Indonesia) for his strong support throughout the years for demand-driven and “just-in-time” policy work that has been carried out under DESP. Technical con- tributions from AusAID-supported consultants, Graham Dawson and John Bladen, are also acknowledged. \ud It should be noted that although inputs of various officials have been incorpo- rated into the report, the policy recommendations in this document do not necessarily reflect the policies of the Government of Indonesia, the Government of the Kingdom of the Netherlands, or the World Bank. \ud The team of authors who produced this report is grateful to the officials and staff of the Ministry of Education and Culture for their overall support. Special thanks are in order to Fasli Jalal, former Vice Minister of Education, who was the visionary behind the Teacher Law that inspired this report and a key supporter of many of the teacher management studies that contributed to it. The current Minister of Education and Culture, Mohammad Nuh; Vice Minister of Education, Musliar Kasim; the Special Advisor to the Minister, Taufik Hanafi; the Head of \ud the Board of Education and Culture, Human Resources Development and Quality Assurance for Education, Syawal Gultom; and the former Director General for Quality Improvement of Teacher and Education Personnel, Baedhowi, played major roles in using the evidence produced to improve the teacher regula- tions. The report also benefited greatly from the inputs of the Ministry of Religious Affairs, the National Development Planning Agency, the Ministry of State Administration Reform, the Ministry of Finance, and the Civil Service Agency, together with inputs of donor agencies that were received during various consultation meetings and policy forum discussions. Key government support came from the directors, the head of centers, and senior key staff of the Ministry responsible for teacher management, quality assurance, and teacher-related stud- ies: Sumarna Suryapranata, Surya Dharma, Hendarman, Unifah Rosyidi, Abi Sujak, Muchlas Samani, Anah Suhaenah, Gogot Suharwoto, Maria Widiani, Poppy Puspitawati, Dian Wahyuni, Santi Ambarukmi, E. Nurzaman, Giri Suryaatmana, Ahmad Dasuki, Bambang Indriyanto, Nugaan Yulia Wardhani Siregar, Hari Setiadi, Burhanudin Tola, Yendri Wirda Burhan, Simon Sili Sabon, Rahmawati, Handayani Sumarno, Rumtini, Yaya Zakaria, and M.S. Sembiring. \ud Insightful comments from stakeholders were provided by Lilian Rahman (Gorontalo district), Sulistiyo (Chair of the Teacher Association of Republic of Indonesia, PGRI), Sahiri Hermawan (PGRI), Arief Rahman (Chair of the Indonesian National Commission for UNESCO), Heri Akhmadi (a member of Parliament), Anies Baswedan (Rector of Paramadina University and Chair of Indonesia Mengajar), Hetty Herawati (Principal of SD Taruna Bangsa), Sudarwan Danim and Anthony Crocker (consultants at the Board of Education and Culture, Human Resources Development and Quality Assurance for Education), Agus Supriatman (Head of the Education Office, Karawang District), Nanda Suhanda (a member of the Karawang District Parliament), Obang Nurbayu (Head of PGRI, Karawang District), and Nanang Muchlis (Chair, Board of Education, Karawang District). \ud The report was improved by detailed feedback from the following principal reviewers: F. Halsey Rogers, Venkatesh Sundararaman, and Helen J. Craig (World Bank); Molly Lee (formerly UNESCO); and Tom Lowrie (Charles Sturt University). Helpful comments were also received from William Wallace, James A. Brumby, and Yasuhiko Matsuda (World Bank). The report was prepared under the guidance of Luis Benveniste, Sector Manager, East Asia and Pacific Region, and the support of Stefan Koeberle (Country Director for Indonesia)

Do female association preferences predict the likelihood of reproduction?

Sexual selection acting on male traits through female mate choice is commonly inferred from female association preferences in dichotomous mate choice experiments. However, there are surprisingly few empirical demonstrations that such association preferences predict the likelihood of females reproducing with a particular male. This information is essential to confirm association preferences as good predictors of mate choice. We used green swordtails (<i>Xiphophorus helleri</i>) to test whether association preferences predict the likelihood of a female reproducing with a male. Females were tested for a preference for long- or short-sworded males in a standard dichotomous choice experiment and then allowed free access to either their preferred or non-preferred male. If females subsequently failed to produce fry, they were provided a second unfamiliar male with similar sword length to the first male. Females were more likely to reproduce with preferred than non-preferred males, but for those that reproduced, neither the status (preferred/non-preferred) nor the sword length (long/short) of the male had an effect on brood size or relative investment in growth by the female. There was no overall preference based on sword length in this study, but male sword length did affect likelihood of reproduction, with females more likely to reproduce with long- than short-sworded males (independent of preference for such males in earlier choice tests). These results suggest that female association preferences are good indicators of female mate choice but that ornament characteristics of the male are also important

Autonomy support, basic need satisfaction and the optimal functioning of adult male and female sport participants: A test of basic needs theory

Grounded in Basic Needs Theory (BNT; Ryan and Deci, American Psychologist, 55, 68–78, 2000a), the present study aimed to: (a) test a theoretically-based model of coach autonomy support, motivational processes and well-/ill being among a sample of adult sport participants, (b) discern which basic psychological need(s) mediate the link between autonomy support and well-/ill-being, and (c) explore gender invariance in the hypothesized model. Five hundred and thirty nine participants (Male = 271;Female = 268; Mage = 22.75) completed a multi-section questionnaire tapping the targeted variables. Structural Equation Modeling (SEM) analysis revealed that coach autonomy support predicted participants’ basic need satisfaction for autonomy, competence and relatedness. In turn, basic need satisfaction predicted greater subjective vitality when engaged in sport. Participants with low levels of autonomy were more susceptible to feeling emotionally and physically exhausted from their sport investment. Autonomy and competence partially mediated the path from autonomy support to subjective vitality. Lastly, the results supported partial invariance of the model with respect to gender