Diana Project Research Articles

Analysing the SEDs of protoplanetary disks with machine learning

Context. The analysis of spectral energy distributions (SEDs) of protoplanetary disks to determine their physical properties is known to be highly degenerate. Hence, a full Bayesian analysis is required to obtain parameter uncertainties and degeneracies. The main challenge here is computational speed, as one proper full radiative transfer model requires at least a couple of CPU minutes to compute. Aims. We performed a full Bayesian analysis for 30 well-known protoplanetary disks to determine their physical disk properties, including uncertainties and degeneracies. To circumvent the computational cost problem, we created neural networks (NNs) to emulate the SED generation process. Methods. We created two sets of MCFOST Monte Carlo radiative transfer disk models to train and test two NNs that predict SEDs for continuous and discontinuous disks, with 18 and 26 free model parameters, respectively. A Bayesian analysis was then performed on 30 protoplanetary disks with SED data collected by the FP7-Space DIANA project to determine the posterior distributions of all parameters. We ran this analysis twice, (i) with old distances and additional parameter constraints as used in a previous study, to compare results, and (ii) with updated distances and free choice of parameters to obtain homogeneous and unbiased model parameters. We evaluated the uncertainties in the determination of physical disk parameters from SED analysis, and detected and quantified the strongest degeneracies. Results. The NNs are able to predict SEDs within ~1 ms with uncertainties of about 5% compared to the true SEDs obtained by the radiative transfer code. We find parameter values and uncertainties that are significantly different from previous values obtained by χ2 fitting. Comparing the global evidence for continuous and discontinuous disks, we find that 26 out of 30 objects are better described by disks that have two distinct radial zones. The analysed sample shows a significant trend for massive disks to have small scale heights, which is consistent with lower midplane temperatures in massive disks. We find that the frequently used analytic relationship between disk dust mass and millimetre-flux systematically underestimates the dust mass for high-mass disks (dust mass ≥10−4 M⊙). We determine how well the dust mass can be determined with our method for different numbers of flux measurements. As a byproduct, we created an interactive graphical tool that instantly returns the SED predicted by our NNs for any parameter combination.

Diana – dispositivo de análise e controle de estufas agrícolas

O cultivo em estufas agrícolas sem o monitoramento adequado, em função do descontrole climático, impossibilita o agricultor à produção adequada de determinados alimentos. Com base nisto, desenvolveu-se o projeto de pesquisa DIANA (Dispositivo de Análise e Controle de Estufas Agrícolas). Considerando que “[...]a capacidade de controlar o ambiente interno da estufa faz com que os resultados sejam melhores dos que os conseguidos em campo aberto” (MURGUERO JUNIOR;2016, p. 150) [7], é através da análise e controle do tempo em uma estufa que se obtêm os melhores resultados em cultivos. O dispositivo DIANA tem por objetivo proporcionar ao usuário um sistema eletrônico que atue na busca por garantir as condições climáticas ideais para a produção em estufas de hortifrutigranjeiros, pois simula-se um microclima desejado em seu interior. O aparelho eletrônico indica ao usuário os dados climáticos em tempo real. Para isto, o sistema conta com sensores de luminosidade, umidade relativa do solo, umidade relativa do ar e temperatura. Após efetuar toda a etapa de monitoramento, o usuário poderá selecionar as condições climáticas que deseja na central do equipamento. Depois de selecionados os valores desejados, o sistema atuará automaticamente, a fim de controlar as propriedades climáticas por meio de atuadores elétricos. O equipamento tem sido trabalhado em escala de bancada e estuda-se sua implantação em escala piloto, ou seja, uma estufa de média escala para fins de testes de germinação, tendo repetição dos mesmos tratamentos em ambiente não controlado, ou seja, mediante as intempéries, para comparação. Portanto, o cultivo controlado em estufas resolve a problemática das intempéries climáticas e propicia ao agricultor e a população um produto de melhor qualidade [8].

Harmonized Landsat 8 and Sentinel-2 Time Series Data to Detect Irrigated Areas: An Application in Southern Italy

Lack of accurate and up-to-date data associated with irrigated areas and related irrigation amounts is hampering the full implementation and compliance of the Water Framework Directive (WFD). In this paper, we describe the framework that we developed and implemented within the DIANA project to map the actual extent of irrigated areas in the Campania region (Southern Italy) during the 2018 irrigation season. For this purpose, we considered 202 images from the Harmonized Landsat Sentinel-2 (HLS) products (57 images from Landsat 8 and 145 images from Sentinel-2). Such data were preprocessed in order to extract a multitemporal Normalized Difference Vegetation Index (NDVI) map, which was then smoothed through a gap-filling algorithm. We further integrated data coming from high-resolution (4 km) global satellite precipitation Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks (PERSIANN)-Cloud Classification System (CCS) products. We collected an extensive ground truth in the field represented by 2992 data points coming from three main thematic classes: bare soil and rainfed (class 0), herbaceous (class 1), and tree crop (class 2). This information was exploited to generate irrigated area maps by adopting a machine learning classification approach. We compared six different types of classifiers through a cross-validation approach and found that, in general, random forests, support vector machines, and boosted decision trees exhibited the best performances in terms of classification accuracy and robustness to different tested scenarios. We found an overall accuracy close to 90% in discriminating among the three thematic classes, which highlighted promising capabilities in the detection of irrigated areas from HLS products.

The Diana project: a legacy for research on gender in entrepreneurship

PurposeThe purpose of this paper is to provide a brief history of the evolution of the Diana Project and the Diana International Research Conference. The authors examine the impact of the publications, conferences and research contributions and consider key factors in the success of this collaborative research organization. They discuss the ongoing legacy, suggesting ways to extend this into the future.Design/methodology/approachThis paper uses an historical narrative and a citation analysis.FindingsThe Diana Project was founded by five women professors in 1999 with the purpose of investigating women’s access to growth capital. Following a series of academic articles, and numerous presentations, the first Diana International Conference was held in Stockholm, Sweden. At this convening, 20 scholars from 13 countries shared their knowledge of women’s entrepreneurship, venture creation and growth, culminating in the first volume of the Diana Book Series. Since then, 14 international conferences have been held, resulting in 10 special issues of top academic journals and 11 books. More than 600 scholars have attended or participated in Diana conferences or publications.Research limitations/implicationsContributions from the Diana International Conferences’ special issues of journals and books have advanced theory across topics, levels, geographies and methods. Articles emerging from Diana scholars are some of the top contributions about women’s entrepreneurship and gender to the field of entrepreneurship. Future research directions are included.Practical implicationsThis analysis demonstrates the success of a unique woman-focused collaborative research initiative and identifies key success factors, suggesting how these might be expanded in the future.Social implicationsTo date, more than 600 scholars have participated in the Diana International Conferences or publications. Diana is the only community dedicated to rigorous and relevant research about gender and women’s entrepreneurship. Going forward, efforts to expand work on education for women’s entrepreneurship, women entrepreneurship faculty and careers, and women entrepreneurs, gender and policy will take place to extend this legacy.Originality/valueThe paper is unique in that it is the first to show the substantial legacy and impact of the Diana project since its inception in 1999. Further, it demonstrates how a feminist approach to entrepreneurial principles can yield insights about this unique research initiative and collaborative organization.

Consistent Dust and Gas Models for Protoplanetary Disks. III. Models for Selected Objects from the FP7 DIANA Project**EU FP7-SPACE-2011 project 284405 “DiscAnalysis” (Analysis and Modeling of Multi-wavelength Observational Data from Protoplanetary Discs).

The European FP7 project DIANA has performed a coherent analysis of a large set of observational data of protoplanetary disks by means of thermo-chemical disk models. The collected data include extinction-corrected stellar UV and X-ray input spectra (as seen by the disk), photometric fluxes, low and high resolution spectra, interferometric data, emission line fluxes, line velocity profiles and line maps, which probe the dust, polycyclic aromatic hydrocarbons (PAHs) and the gas in these objects. We define and apply a standardized modeling procedure to fit these data by state-of-the-art modeling codes (ProDiMo, MCFOST, MCMax), solving continuum and line radiative transfer (RT), disk chemistry, and the heating and cooling balance for both the gas and the dust. 3D diagnostic RT tools (e.g., FLiTs) are eventually used to predict all available observations from the same disk model, the DIANA-standard model. Our aim is to determine the physical parameters of the disks, such as total gas and dust masses, the dust properties, the disk shape, and the chemical structure in these disks. We allow for up to two radial disk zones to obtain our best-fitting models that have about 20 free parameters. This approach is novel and unique in its completeness and level of consistency. It allows us to break some of the degeneracies arising from pure Spectral Energy Distribution (SED) modeling. In this paper, we present the results from pure SED fitting for 27 objects and from the all inclusive DIANA-standard models for 14 objects. Our analysis shows a number of Herbig Ae and T Tauri stars with very cold and massive outer disks which are situated at least partly in the shadow of a tall and gas-rich inner disk. The disk masses derived are often in excess to previously published values, since these disks are partially optically thick even at millimeter wavelength and so cold that they emit less than in the Rayleigh–Jeans limit. We fit most infrared to millimeter emission line fluxes within a factor better than 3, simultaneously with SED, PAH features and radial brightness profiles extracted from images at various wavelengths. However, some line fluxes may deviate by a larger factor, and sometimes we find puzzling data which the models cannot reproduce. Some of these issues are probably caused by foreground cloud absorption or object variability. Our data collection, the fitted physical disk parameters as well as the full model output are available to the community through an online database (http://www.univie.ac.at/diana).

The gender gap in venture capital- progress, problems, and perspectives

Financial capital is a critical resource for growing firms, yet women entrepreneurs received very small percent of the funding. This research updates earlier research by the Diana Project using a data base of all venture capital funded firms in the US. We compare funding in those firms led by men and women across stage, sector, state, region and outcomes. Results show women have made progress in attracting venture capital, although there is still a significant gender gap. A research framework and future research directions are proposed.

Leveling the entrepreneurial playing fieldWomen’s Entrepreneurship in the 21st Century: An International Multi-Level Research Analysisedited by Kate V. Lewis, Colette Henry, Elizabeth J. Gatewood and John Watson

Why do businesses started by women tend to remain smaller, both in revenue and employees, than the businesses initiated by men? Why, in all countries surveyed, is the rate of men’s venture creation greater than women’s? Identifying the answers to these deceptively simple questions requires a serious, far reaching, academic exploration of the complex factors influencing women’s entrepreneurship. In 1999, a group of scholars launched a multi-university research consortium named the Diana Project. Since its founding, the Diana Project has engaged in comprehensive research, convened conferences, expanded its focus to include international studies, and published four books. The most recent volume (the subject of this review) derives from the 2012 Diana International Conference held in Perth, Australia. The Diana Project is continuing its work: the group met in Sweden in the summer of 2014. Today, it is impossible to engage with questions concerning the global economy and social change and not be paying attention to women’s entrepreneurship. Jackie Vandenberg, writing in the Harvard Business Review (< https://hbr.org/2013/09/global-rise-of-female-entrepreneurs >), reported that in the period 2008–12 the number of times women entrepreneurs were mentioned in the global press soared six-fold. A consensus is emerging in international public policy circles that enabling and enhancing women’s contributions to business development, particularly through entrepreneurship, is key to growing global economic opportunities. In recognition of the obvious fact that women represent half of the world’s talent pool, the World Economic Forum asserts that: … a nation’s competitiveness in the long term depends significantly on whether and how it educates and utilizes its women. (< https://agenda.weforum.org/topic/global-issues/gender-parity/ >)

Asthma Diagnosis in Spain: Survey of Opinions, Attitudes and Knowledge among Primary Care Physicians

Background: Asthma is frequently misdiagnosed. Peak expiratory flow (PEF) measurement is easy and very useful for asthma diagnosis in primary care. Objectives: The DIANA project aimed to assess the impact of a course on PEF measurement among primary care physicians in Spain. Methods: A 7-item questionnaire was sent to selected primary care physicians (Phase A). Respondents were then invited to take a web-based course on PEF in asthma diagnosis. Finally, the questionnaire was again sent to all physicians (Phase B). Questionnaires also asked for demographical data such as age, sex, speciality, route of access to speciality, and geographical area. A comparative statistical analysis was performed on the results of both questionnaires. An extended analysis was performed later. Answers were analysed by percentages and using McNemar’s test. The planned duration of the project was one year. Results: No statistically significant differences in percentages between the two phases were found for Items 1 (related to asthma diagnosis) and 4 (related to availability and use of PEF meter). However, for Item 2 (related to diagnosis of occupational asthma) differences were significant (p<0.05), with an odds ratio (OR) of 1.50 for those participating in Phase B. Differences were also significant (p<0.05) for those who took the course, with an OR of 1.37. For Item 3 (related to the usefulness of measuring daily variability of PEF), there were also significant differences (p<0.05) between the two phases, with an OR of 1.39. There were also significant differences (p<0.05) for those who took the course, with an OR of 1.53. Conclusions: The first four results of the survey showed that educational intervention may improve knowledge of the usefulness of PEF in asthma diagnosis among primary care physicians. However, the high percentages of correct answers among those who did not take the course merit further investigation.

Acoustic Sensor Planning for Gunshot Location in National Parks: A Pareto Front Approach

In this paper, we propose a solution for gunshot location in national parks. In Spain there are agencies such as SEPRONA that fight against poaching with considerable success. The DiANa project, which is endorsed by Cabaneros National Park and the SEPRONA service, proposes a system to automatically detect and locate gunshots. This work presents its technical aspects related to network design and planning. The system consists of a network of acoustic sensors that locate gunshots by hyperbolic multi-lateration estimation. The differences in sound time arrivals allow the computation of a low error estimator of gunshot location. The accuracy of this method depends on tight sensor clock synchronization, which an ad-hoc time synchronization protocol provides. On the other hand, since the areas under surveillance are wide, and electric power is scarce, it is necessary to maximize detection coverage and minimize system cost at the same time. Therefore, sensor network planning has two targets, i.e., coverage and cost. We model planning as an unconstrained problem with two objective functions. We determine a set of candidate solutions of interest by combining a derivative-free descent method we have recently proposed with a Pareto front approach. The results are clearly superior to random seeding in a realistic simulation scenario.

Diana: a symbol of women entrepreneurs’ hunt for knowledge, money, and the rewards of entrepreneurship

This article discusses the questions and issues that prompted the founding of the Diana Project, a multi-university research program aimed at identifying factors that support and enable high growth in women-led ventures. Despite the fact that women business owners comprise a significant portion of the economy, women face challenges in acquiring the resources needed to expand their businesses. This article details both the myths and realities associated with women’s entrepreneurship in their quest for growth. In particular, we examine the strategies that women entrepreneurs use to position their firms for growth, especially those strategies related to growth capital. Our results show that women seeking venture capital (VC) have degrees, graduate degrees, and experience that should not preclude them from obtaining financing. We also found that even though women-led businesses are frequently clustered in industries less attractive to financiers, women seeking equity funding are in the appropriate industries. Further, women spend a considerable amount of time using both formal and informal networks in their search for capital and in seeking capital. Because of the importance of the VC industry as a provider of growth capital and its reliance on its network for investment referrals, we also examined the participation and role of women as decision-makers in industry. Women’s participation in the VC industry has not kept pace with industry growth, and women have exited the industry at a faster rate than men, thus creating a significant barrier for women entrepreneurs in that it is less likely that their networks will overlap with the financial supplier networks, despite any effort they may expend networking and seeking capital.

The Diana Project: pioneering women studying pioneering women

The 2007 winner of the International Award for Entrepreneurship and Small Business Research is the Diana Project team (Candida Brush, Nancy Carter, Elizabeth Gatewood, Patricia Greene and Myra Hart). The Diana Project builds on the vast experience of the team in the field of entrepreneurship in general and women entrepreneurship, business growth and venture capital in particular. The Diana Project has investigated the supply and demand side of growth capital for women entrepreneurs. The research contributes to entrepreneurship theory as well as to practice, filling a void in knowledge on growth-oriented women entrepreneurship. In this article we present and discuss the research contribution of the Diana Project, in the areas of entrepreneurship, women entrepreneurship and venture capital. We specifically discuss the value of researching a specific group of women entrepreneurs, those who want to grow their businesses, that very clearly demonstrates the positive potential of female entrepreneurship. The Diana Project has also moved research on women’s entrepreneurship forward since its framework does not treat women entrepreneurs as “other,” i.e., the project does not presuppose that women’s entrepreneurship is similar to or different from men’s entrepreneurship. It assumes that women’s entrepreneurship is entrepreneurship and studies it from that point of view.

Gatekeepers of Venture Growth: A Diana Project Report on the Role and Participation of Women in the Venture Capital Industry

Women have received a disproportionately low share of available venture capital in the United States. This study provides the first overview of women decision makers in the venture capital industry. Data from Pratt's Guide to Venture Capital Sources for 1995 and 2000 was analyzed to identify the numbers and characteristics of women in management positions. In addition, high-profile women venture capitalists were interviewed.The study tested the hypothesis that the presence of more women in decision-making roles in the venture capital industry would provide greater access to capital for women entrepreneurs. Three key points were considered: (1) whether highly visible, experienced women venture capitalists exist in the venture capital industry; (2) whether such women venture capitalists influence decision making in their firms; and (3) whether such women venture capitalists increase the flow of women-led deals to their firms.Results indicate that the venture capital industry is overwhelmingly male; that pre-existing relationships provide an important link between entrepreneurs and venture capitalists; and that women venture capitalists do not give preferential treatment to women, although 70 percent are in partnerships that have closed deals with women-led companies. It appears that the presence of more women venture capitalists would lead to the following: increased network connections between venture capitalists and women entrepreneurs; increased numbers of proposals to women venture capitalists; a greater likelihood that firms will invest in women-owned firms; an increase in women's access to capital; and a more powerful voice for women in the country's entrepreneurial progress.

The Diana Project: Women Business Owners and Equity Capital: The Myths Dispelled

This report from the Diana Project explores the extent of equity investments in women-owned businesses. Surveyed were 1,700 applicants to the 2000 Springboard forums to examine the current state of venture capital for women entrepreneurs interested in, and capable of, high growth venturing, in hopes of debunking myths about women and venture capital. Eight myths about women and equity capital are identified: (1) women don't want to own high growth businesses; (2) women don't have the right educational backgrounds to build large ventures; (3) women don't have the right types of experience to build large ventures; (4) women aren't in the network and lack the social contacts to build a credible venture; (5) women don't have the financial savvy or resources to start high growth businesses; (6) women don't submit business plans to equity providers; (7) women-owned ventures are in industries unattractive to venture capitalists; and (8) women are not a force in the venture capital industry. Each of these myths is examined, and many are shown to be false or undergoing change. Nonetheless, a disparity exists between men- and women-owned ventures and their access to funding. Six recommendations to ensure equity investment in all entrepreneurial ventures are offered.

Growth-oriented women entrepreneurs and their businesses: a global research perspective

Contents: PART I: COUNTRY REPORTS ON WOMEN'S ENTREPRENEURSHIP 1. Introduction: The Diana Project International Candida G. Brush, Nancy M. Carter, Elizabeth J. Gatewood, Patricia G. Greene and Myra M. Hart 2. Women's Entrepreneurship in Australia: Present and Their Future Mary Barrett 3. Women's Entrepreneurship in Canada: Progress, Puzzles and Priorities Jennifer E. Jennings and Michelle Provorny Cash 4. State of the Art of Women's Entrepreneurship, Access to Financing and Financing Strategies in Denmark Helle Neergaard, Kent T. Nielsen and John I. Kjeldsen 5. Women's Entrepreneurship in Finland Anne Kovalainen and Pia Arenius 6. Women's Entrepreneurship in Germany: Progress in a Still Traditional Environment Friederike Welter 7. Women's Entrepreneurship in Norway: Recent Trends and Future Challenges Lene Foss and Elisabet Ljunggren 8. Women's Entrepreneurship in the United States Candida G. Brush, Nancy M. Carter, Elizabeth J. Gatewood, Patricia G. Greene and Myra M. Hart PART II: RESEARCH TOPICS ON THE GROWTH OF WOMEN-OWNED BUSINESSES 9. Comparing the Growth and External Funding of Male- and Female-controlled SMEs in Australia John Watson, Rick Newby and Ann Mahuka 10. Builders and Leaders: Six Case Studies of Men and Women Small Proprietors in the Bulgarian Construction Industry Tatiana S. Manolova 11. Access to Finance for Women Entrepreneurs in Ireland: A Supply-Side Perspective Colette Henry, Kate Johnston and Angela Hamouda 12. Women Entrepreneurs in New Zealand: Private Capital Perspectives Anne de Bruin and Susan Flint-Hartle 13. The Supply of Finance of Women-led Ventures: The Northern Ireland Experience Claire M. Leitch, Frances Hill and Richard T. Harrison 14. Female Entrepreneurial Growth Aspirations in Slovenia: An Unexploited Resource Polona Tominc and Miroslav Rebernik 15. Spain - The Gender Gap in Small Firms' Resources and Performance: Still a Reality? Cristina Diaz and Juan J. Jimenez 16. Gender, Entrepreneurship and Business Finance: Investigating the Relationship between Banks and Entrepreneurs in the UK Sara Carter, Eleanor Shaw, Fiona Wilson and Wing Lam Index

Clearing the hurdles: women building high-growth businesses

Women Building High-Growth Businesses “Even in the 21st century, much of the world still systematically excludes 50 percent of the smartest people from full responsibility. Entrepreneurship rewards excellence and results, not gender, and this book is a wonderful gift to women who would like to respond to corporate America by saying, 'Thanks, I'll do it myself'.” --Jim Collins, Author, Good to Great, and Co-author, Built to Last “Savvy and inspirational, Clearing the Hurdles is an important book for women intent on growing new businesses. The team of talented authors provides information, insights, and advice that will educate, motivate, and challenge women aspiring to become successful entrepreneurs.” --Laura Tyson, Dean, London Business School “With women creating new businesses at a faster rate than males, it is imperative that today's venture capitalists take an active role in mentoring and recruiting women to become venture capitalists, business owners, technologists, entrepreneurs, and government leaders. Clearing the Hurdles is not only a wake up call; it is a roadmap to start this long overdue project.” --Mark Heesen, President, National Venture Capital Association “Clearing the Hurdles examines all elements behind the lack of access to capital for women entrepreneurs who want to build high-growth companies. If you are a woman who has a vision for a high-potential business, this book was written for you.” --Connie Duckworth, Kathy Elliott, Sharon Whiteley, Founders, 8Wings Enterprises, and Co-authors, The Old Girls Network: Insider Advice for Women Building Businesses in a Man's World “Clearing the Hurdles debunks the myths and defines the barriers that entrepreneurs confront--a perfect roadmap for women embarking on the entrepreneurial journey.” --Kay Koplovitz, Founder, USA Networks, and former Chair, National Women's Business Council Starting, funding, and growing a new venture are significant challenges for every entrepreneur. For women, the hurdles are even higher, due to widely held perceptions about them, their capabilities, and their businesses. Now, five leading experts on women entrepreneurs offer systematic solutions to the challenges, offering timely advice to women dedicated to achieving success and claiming the rewards.Clearing the Hurdles draws on five years of original research, performed as part of the Diana Project--a major initiative that explores ways women grow businesses.The authors identify key factors associated with funding, growth, and success: the founder's goals, expertise, and commitment; strategic direction; team building; effective use of networks; and access to capital. Most important, they offer concrete strategies for overcoming obstacles: strategies proven in the marketplace by women entrepreneurs.Wealth creation: Don't get left out!Learn what it takes to build your high-growth businessGet credibleFill the technical and management gaps in your expertiseGet strategicChoose the right business, build the right planGet connectedLink yourself to the right resources, networks, and peopleGet over the funding hurdles. This book is a training manual for women who want to claim their place as winners in the entrepreneurial challenge.

Predictors of Red Cell Folate Level in Women Attempting Pregnancy

Brown, Judith E.; Jacobs, David R. Jr; Hartman, Terryl J.; Barosso, Geralyn M.; Stang, Jamie S.; Gross, Myron D.; Zeuske, Melanie A. Author Information

Recruitment, retention and characteristics of women in a prospective study of preconceptional risks to reproductive outcomes: experience of the Diana Project

Preterm delivery, low birthweight, and intrauterine growth retardation are common and recalcitrant problems in many countries. Although much remains to be learned, we know particularly little about the relationships between preconceptional and early pregnancy exposures and these and other reproductive outcomes. The study presented here was primarily designed to investigate the relationships between nutritional exposures measured before and during pregnancy and reproductive outcomes. This paper describes methods used to recruit the required 1000 preconceptional women from the collaborating health maintenance organisation (HMO) and the retention of participants in this time-intensive study. The results presented demonstrate that an adequate completion rate (66.3%), and a remarkably representative sample of women that poses few threats to the study's validity, can be obtained by population-based recruitment of women from an HMO.

Predictors of red cell folate level in women attempting pregnancy.

To identify predictors of red cell folate level in women attempting to become pregnant. Cohort study. A health maintenance organization serving the Minneapolis-St Paul, Minn, area. A total of 189 healthy, primarily white women aged 22 to 35 years enrolled in the Diana Project, a population-based prospective study of preconceptional and prenatal risks to reproductive outcomes. The sample represents 189 of 219 enrolled women who were sequentially selected from the total Diana Project sample to receive additional laboratory analyses. Red cell folate level. Folic acid supplements, folic acid intake from fortified cereals, vitamin C supplements, and serum zinc level (inverse) were found to predict red cell folate levels. Previous research has shown that red cell folate levels higher than 906 nmol/L (400 ng/mL) may be optimal for the prevention of folate-responsive neural tube defects. For folic acid supplement users, folate intakes of 450 microg per day and higher corresponded to these protective levels of red cell folate. In nonusers of supplements, intakes of more than 500 microg of folate per day from foods and folic acid-fortified cereals may be needed to attain red cell folate levels higher than 906 nmol/L (400 ng/mL). Red cell folate levels higher than 906 nmol/L (400 ng/mL) were primarily found in women who took folic acid supplements. Only 1 in 4 women had red cell folate levels higher than 906 nmol/L (400 ng/mL), while 1 in 8 had red cell folate levels indicative of a negative folate balance. Addition of a daily, 400-microg folic acid supplement to the usual diet would result in red cell folate levels over 906 nmol/L (400 ng/mL) in a majority of women in this study. Supplementation of diets of women of childbearing potential with 400 microg of folic acid per day would effectively raise red cell folate to levels associated with a low risk of folate-responsive neural tube defects. Protective levels of red cell folate may also be obtained by ample consumption of vegetables, fruits, and folic acid-fortified breakfast cereals. Efforts to increase folic acid supplement use and folate consumption among women of childbearing potential must go beyond fortification of refined cereal and grain products and reach women within all educational and income groups.

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A Food Frequency Questionnaire can Detect Pregnancy-Related Changes in Diet

Objective To determine whether a food frequency questionnaire (FFQ) can detect changes in dietary intake before pregnancy to mid-pregnancy relative to a 4-day food record. Design FFQs and 4-day, weighed food records (4DRs) were completed during similar time intervals before pregnancy and again near mid-pregnancy by women served by a large health maintenance organization in the Minneapolis-St Paul, Minn, area. The outcome of interest was change in the intake of energy and 16 nutrients. Participants were members of the Diana Project, a prospective study of relationships among prepregnancy and pregnancy nutritional and other exposures and reproductive outcomes. Fifty-six (51%) of the eligible women completed the study. Subjects Well-educated, healthy, white women. Statistical analyses performed Spearman rank order correlations. Results Mean energy and nutrient intake levels estimated using the 4DR were generally higher than those estimated using the FFQ. Correlations between change in energy and nutrient intakes measured by the 4DR and FFQ ranged from 0.75 for vitamin C to 0.02 for cholesterol and averaged 0.48. Applications Comparisons with 4DRs indicate that the FFQ used in this study is appropriate for obtaining reliable estimates of prepregnancy to mid-pregnancy changes in intake of energy and a number of nutrients in similar groups of women. J Am Diet Assoc. 1996; 96:262-266.