The Cost of Jointness and How to Manage It

Although joint programs are typically formed to reduce costs, recent studies have suggested that joint programs experience larger cost growth than non-joint programs. To explain this phenomenon, we present a model that attributes joint program cost growth to agencies’ actions to maintain or regain their autonomy. We use this model to motivate principles for architecting joint programs and outline a process that can be used to identify opportunities for reforming current joint programs or for establishing new ones. Finally, we apply our approach to analyze joint program options for NOAA’s low-earth orbiting weather satellite program and in doing so, identify several risks facing NOAA’s current program and strategies for mitigating them.Massachusetts Institute of Technology (Sandia Corporation Excellence in Engineering Graduate Fellowship)Skolkovo Institute of Science and Technolog

Rings, modules, and algebras in infinite loop space theory

We give a new construction of the algebraic $K$-theory of small permutative categories that preserves multiplicative structure, and therefore allows us to give a unified treatment of rings, modules, and algebras in both the input and output. This requires us to define multiplicative structure on the category of small permutative categories. The framework we use is the concept of multicategory, a generalization of symmetric monoidal category that precisely captures the multiplicative structure we have present at all stages of the construction. Our method ends up in Smith's category of symmetric spectra, with an intermediate stop at a new category that may be of interest in its own right, whose objects we call symmetric functors.Comment: 59 pages, 1 figur

PENGARUH PENAMBAHAN LENSA NOZZLE DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415 TERHADAP HASIL DAYA LISTRIK TURBIN ANGIN SUMBU HORISONTAL

Danur Lambang Pristiandaru. PENGARUH PENAMBAHAN LENSA NOZZLE TURBIN ANGIN DAN JUMLAH BLADE AIRFOIL TIPE NACA 4415 TERHADAP HASIL DAYA LISTRIK. Skripsi, Fakultas Keguruan dan Ilmu Pendidikan Universitas Sebelas Maret Surakarta. Januari 2016 Tujuan penelitian ini adalah: (1) Menyelidiki pengaruh jumlah blade pada turbin angin non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang dihasilkan. (2) Menyelidiki pengaruh penambahan lensa nozzle pada turbin angin non-twisted blade tipe airfoil NACA 4415 terhadap daya listrik yang dihasilkan turbin angin. (3) Menyelidiki pengaruh bersama (interaksi) antara penambahan lensa nozzle dan jumlah blade terhadap daya listrik yang dihasilkan turbin angin. Penelitian ini menggunakan metode deskriptif kuantitatif. Sampel dalam penelitian ini adalah Turbin Angin Sumbu Horisontal (TASH) dengan desain blade airfoil NACA 4415 non-twisted. 3 desain lensa nozzle digunakan untuk mengetahui pengaruhnya terhadap peningkatan daya listrik TASH. Terdapat 3 variasi jumlah blade yaitu jumlah blade 2, jumlah blade 3, dan jumlah blade 4. Variasi kecepatan angin yang digunakan dalam penelitian ini adalah 2,5 m/s, 3,5 m/s, dan 4,5 m/s. Data diperoleh dengan melakukan pengujian TASH menggunakan angin rekayasa, daya listrik yang dihasilkan dibaca dan direkam oleh data logger. Data yang diperoleh dari hasil penelitian dimasukkan ke dalam tabel dan ditampilkan dalam bentuk grafik, kemudian dianalisis. Berdasarkan hasil penelitian dapat disimpulkan bahwa: (1) Adanya pengaruh variasi jumlah blade terhadap daya listrik turbin angin. TASH 3 blade menghasilkan daya listrik yang paling besar yaitu 0,7222 W pada kecepatan angin 4,5 m/s. (2) Adanya pengaruh penambahan lensa nozzle terhadap turbin angin. Lensa nozzle mampu meningkatkan hasil daya listrik turbin angin semua jenis variasi jumlah blade dibandingkan turbin angin tanpa lensa nozzle. (3) Ada pengaruh bersama yang signifikan antara variasi jumlah blade dan variasi jenis lensa terhadap daya listrik turbin angin. TASH 3 blade dengan lensa C pada kecepatan angin 4,5 m/s memiliki daya listrik tertinggi yaitu sebesar 0,82041 W. Daya listrik tersebut meningkat 13,60% dibanding TASH 3 blade tanpa penambahan lensa, yaitu 0,7222 W. Kata kunci: Turbin Angin, Lensa Nozzle, Daya Listrik, Data Logge

Ecological Invasion, Roughened Fronts, and a Competitor's Extreme Advance: Integrating Stochastic Spatial-Growth Models

Both community ecology and conservation biology seek further understanding of factors governing the advance of an invasive species. We model biological invasion as an individual-based, stochastic process on a two-dimensional landscape. An ecologically superior invader and a resident species compete for space preemptively. Our general model includes the basic contact process and a variant of the Eden model as special cases. We employ the concept of a "roughened" front to quantify effects of discreteness and stochasticity on invasion; we emphasize the probability distribution of the front-runner's relative position. That is, we analyze the location of the most advanced invader as the extreme deviation about the front's mean position. We find that a class of models with different assumptions about neighborhood interactions exhibit universal characteristics. That is, key features of the invasion dynamics span a class of models, independently of locally detailed demographic rules. Our results integrate theories of invasive spatial growth and generate novel hypotheses linking habitat or landscape size (length of the invading front) to invasion velocity, and to the relative position of the most advanced invader.Comment: The original publication is available at www.springerlink.com/content/8528v8563r7u2742

Exploring self-determined solutions to service and system challenges to promote social and emotional wellbeing in Aboriginal and Torres Strait Islander people: a qualitative study

PUBLISHED 22 September 2023Introduction: Many Aboriginal and Torres Strait Islander people living on Kaurna Country in northern Adelaide experience adverse health and social circumstances. The Taingiwilta Pirku Kawantila study sought to understand challenges facing Aboriginal and Torres Strait Islander communities and identify solutions for the health and social service system to promote social and emotional wellbeing. Methods: This qualitative study applied Indigenous methodologies undertaken with Aboriginal and Torres Strait Islander governance and leadership. A respected local Aboriginal person engaged with Aboriginal and Torres Strait Islander community members and service providers through semi-structured interviews and yarning circles that explored community needs and challenges, service gaps, access barriers, success stories, proposed strategies to address service and system challenges, and principles and values for service design. A content analysis identified the breadth of challenges in addition to describing key targets to empower and connect communities and optimize health and social services to strengthen individual and collective social and emotional wellbeing. Results: Eighty-three participants contributed to interviews and yarning circles including 17 Aboriginal community members, 38 Aboriginal and Torres Strait Islander service providers, and 28 non-Indigenous service providers. They expressed the need for codesigned, strengths-based, accessible and flexible services delivered by Aboriginal and Torres Strait Islander workers with lived experience employed in organisations with Aboriginal and Torres Strait Islander leadership and governance. Community hubs and cultural events in addition to one-stop-shop service centres and pre-crisis mental health, drug and alcohol and homelessness services were among many strategies identified. Conclusion: Holistic approaches to the promotion of social and emotional wellbeing are critical. Aboriginal and Torres Strait Islander people are calling for places in the community to connect and practice culture. They seek culturally safe systems that enable equitable access to and navigation of health and social services. Aboriginal and Torres Strait Islander workforce leading engagement with clients is seen to safeguard against judgement and discrimination, rebuild community trust in the service system and promote streamlined access to crucial services.Anna P. Dawson, Eugene Warrior, Odette Pearson, Mark A. Boyd, Judith Dwyer, Kim Morey, Tina Brodie, Kurt Towers, Sonia Waters, Cynthia Avila, Courtney Hammond, Katherine J. Lake, Uncle, Frank Lampard, Uncle, Frank Wanganeen, Olive Bennell, Darrien Bromley, Toni Shearing, Nathan Rigney, Schania Czygan, Nikki Clinch, Andrea Pitson, Alex Brown and Natasha J. Howar

Mapping subnational HIV mortality in six Latin American countries with incomplete vital registration systems

BackgroundHuman immunodeficiency virus (HIV) remains a public health priority in Latin America. While the burden of HIV is historically concentrated in urban areas and high-risk groups, subnational estimates that cover multiple countries and years are missing. This paucity is partially due to incomplete vital registration (VR) systems and statistical challenges related to estimating mortality rates in areas with low numbers of HIV deaths. In this analysis, we address this gap and provide novel estimates of the HIV mortality rate and the number of HIV deaths by age group, sex, and municipality in Brazil, Colombia, Costa Rica, Ecuador, Guatemala, and Mexico.MethodsWe performed an ecological study using VR data ranging from 2000 to 2017, dependent on individual country data availability. We modeled HIV mortality using a Bayesian spatially explicit mixed-effects regression model that incorporates prior information on VR completeness. We calibrated our results to the Global Burden of Disease Study 2017.ResultsAll countries displayed over a 40-fold difference in HIV mortality between municipalities with the highest and lowest age-standardized HIV mortality rate in the last year of study for men, and over a 20-fold difference for women. Despite decreases in national HIV mortality in all countries-apart from Ecuador-across the period of study, we found broad variation in relative changes in HIV mortality at the municipality level and increasing relative inequality over time in all countries. In all six countries included in this analysis, 50% or more HIV deaths were concentrated in fewer than 10% of municipalities in the latest year of study. In addition, national age patterns reflected shifts in mortality to older age groups-the median age group among decedents ranged from 30 to 45years of age at the municipality level in Brazil, Colombia, and Mexico in 2017.ConclusionsOur subnational estimates of HIV mortality revealed significant spatial variation and diverging local trends in HIV mortality over time and by age. This analysis provides a framework for incorporating data and uncertainty from incomplete VR systems and can help guide more geographically precise public health intervention to support HIV-related care and reduce HIV-related deaths.Peer reviewe

Mapping child growth failure across low- and middle-income countries

Childhood malnutrition is associated with high morbidity and mortality globally1. Undernourished children are more likely to experience cognitive, physical, and metabolic developmental impairments that can lead to later cardiovascular disease, reduced intellectual ability and school attainment, and reduced economic productivity in adulthood2. Child growth failure (CGF), expressed as stunting, wasting, and underweight in children under five years of age (0�59 months), is a specific subset of undernutrition characterized by insufficient height or weight against age-specific growth reference standards3�5. The prevalence of stunting, wasting, or underweight in children under five is the proportion of children with a height-for-age, weight-for-height, or weight-for-age z-score, respectively, that is more than two standard deviations below the World Health Organization�s median growth reference standards for a healthy population6. Subnational estimates of CGF report substantial heterogeneity within countries, but are available primarily at the first administrative level (for example, states or provinces)7; the uneven geographical distribution of CGF has motivated further calls for assessments that can match the local scale of many public health programmes8. Building from our previous work mapping CGF in Africa9, here we provide the first, to our knowledge, mapped high-spatial-resolution estimates of CGF indicators from 2000 to 2017 across 105 low- and middle-income countries (LMICs), where 99 of affected children live1, aggregated to policy-relevant first and second (for example, districts or counties) administrative-level units and national levels. Despite remarkable declines over the study period, many LMICs remain far from the ambitious World Health Organization Global Nutrition Targets to reduce stunting by 40 and wasting to less than 5 by 2025. Large disparities in prevalence and progress exist across and within countries; our maps identify high-prevalence areas even within nations otherwise succeeding in reducing overall CGF prevalence. By highlighting where the highest-need populations reside, these geospatial estimates can support policy-makers in planning interventions that are adapted locally and in efficiently directing resources towards reducing CGF and its health implications. © 2020, The Author(s)