1,756 research outputs found
The New Meteor Radar at Penn State: Design and First Observations
In an effort to provide new and improved meteor radar sensing capabilities, Penn State has been developing advanced instruments and technologies for future meteor radars, with primary objectives of making such instruments more capable and more cost effective in order to study the basic properties of the global meteor flux, such as average mass, velocity, and chemical composition. Using low-cost field programmable gate arrays (FPGAs), combined with open source software tools, we describe a design methodology enabling one to develop state-of-the art radar instrumentation, by developing a generalized instrumentation core that can be customized using specialized output stage hardware. Furthermore, using object-oriented programming (OOP) techniques and open-source tools, we illustrate a technique to provide a cost-effective, generalized software framework to uniquely define an instrument s functionality through a customizable interface, implemented by the designer. The new instrument is intended to provide instantaneous profiles of atmospheric parameters and climatology on a daily basis throughout the year. An overview of the instrument design concepts and some of the emerging technologies developed for this meteor radar are presented
Studies on a fusarium disease of corn and sorghum (Preliminary)
A new fusarium disease of corn made its appearance in Iowa, during the season of 1914, seriously injuring the corn crop 01\u27 the state and causing a loss estimated at more than $15,000,000. It was not confined to Iowa, for reports of a similar disease were sent to the Iowa Agricultural Experiment station by H. B. Clark of Blair, Neb., who found an abundance of it there and elsewhere in that state. One of the authors observed the fusarium that same season in western I Illinois and northern Missouri and Dr. E. C. Stakman reported that it occurred in Minnesota. In the following year, 1915, the disease was again abundant, tho not as severe as in 1914
Corn Stalk and Corn Root Diseases in Iowa
Although it has been generally believed that corn is Jess subject to the attacks of fungus than any other agricultural crop, it is estimated that corn smut, corn rust and bacterial disease damage the crops in Iowa to the extent of $8,000,000 annually. In 1914 the attention of the Botanical section of the Iowa Agricultural Experiment Station was called to a new and important disease attacking corn which was later found to be wide spread in the state, working great damage
Anaemia in Pregnancy: Factors Associated with Maternal Anaemia in the Dadaab Refugee Camps, Kenya (2001-2002)
Power-law distributions in empirical data
Power-law distributions occur in many situations of scientific interest and
have significant consequences for our understanding of natural and man-made
phenomena. Unfortunately, the detection and characterization of power laws is
complicated by the large fluctuations that occur in the tail of the
distribution -- the part of the distribution representing large but rare events
-- and by the difficulty of identifying the range over which power-law behavior
holds. Commonly used methods for analyzing power-law data, such as
least-squares fitting, can produce substantially inaccurate estimates of
parameters for power-law distributions, and even in cases where such methods
return accurate answers they are still unsatisfactory because they give no
indication of whether the data obey a power law at all. Here we present a
principled statistical framework for discerning and quantifying power-law
behavior in empirical data. Our approach combines maximum-likelihood fitting
methods with goodness-of-fit tests based on the Kolmogorov-Smirnov statistic
and likelihood ratios. We evaluate the effectiveness of the approach with tests
on synthetic data and give critical comparisons to previous approaches. We also
apply the proposed methods to twenty-four real-world data sets from a range of
different disciplines, each of which has been conjectured to follow a power-law
distribution. In some cases we find these conjectures to be consistent with the
data while in others the power law is ruled out.Comment: 43 pages, 11 figures, 7 tables, 4 appendices; code available at
http://www.santafe.edu/~aaronc/powerlaws
Effect of medical student preference on rural clinical school experience and rural career intentions
Introduction: The key parameter for rural clinical schools (RCSs) is to provide at least 1 year of clinical training in rural areas for 25% of Australian Commonwealth supported medical students with the intent to influence future rural medical workforce outcomes. The objective of this study was to describe the association between a medical student’s selection preference and their RCS experience and rural career intent.
Methods: Medical students completing an RCS placement in 2012 and 2013 were encouraged to complete a survey regarding their experience and future career intent. Data were analysed to compare medical students for whom the RCS was their first choice with students who described the RCS as other than their first preference.
Results: Students for whom RCS was their first choice (724/1092) were significantly more likely to be female, come from a rural background and be from an undergraduate program. These students reported more positive experiences of all aspects of the RCS program (costs, access, support and networks, safety) and were 2.36 times more likely to report intentions to practice in a non-metropolitan area (odds ratio(OR)=2.36 (95% confidence interval(CI)=1.82–3.06), p\u3c0.001). This was true for students of rural (OR=3.11 (95%CI=1.93–5.02), p\u3c0.001) and metropolitan backgrounds (OR=2.07 (95%CI=1.48–2.89), p\u3c0.001). More students in the first-choice group (68.8%) intended to practice in a regional area (not a capital or major city), significantly higher than the 48.4% of participants in the other-preference group (χ2 (1) 42.79, p\u3c0.001).
Conclusions: The decision to choose an RCS placement is a marker of rural career intention and a positive rural training experience for students of both rural and metropolitan backgrounds. It may be important to identify other-preference students and their specific social support needs to ensure a positive perception of a future rural career
Reflections on a Mentoring Partnership Journey
This commentary offers reflection on the mentoring partnership journey between a senior Fellow of the American Academy of Health Behavior (AAHB) and three early- or mid-career AAHB members. Their partnership was supported by the AAHB Research Scholars Mentorship Program. The authors discuss the nature of their working relationship, products they generated, and other lessons learned from the experience. The authors also offer their perspectives on effective mentorship characteristics
The REFANI-N study protocol: a cluster-randomised controlled trial of the effectiveness and cost-effectiveness of early initiation and longer duration of emergency/seasonal unconditional cash transfers for the prevention of acute malnutrition among children, 6-59 months, in Tahoua, Niger.
BACKGROUND: The global burden of acute malnutrition among children remains high, and prevalence rates are highest in humanitarian contexts such as Niger. Unconditional cash transfers are increasingly used to prevent acute malnutrition in emergencies but lack a strong evidence base. In Niger, non-governmental organisations give unconditional cash transfers to the poorest households from June to September; the 'hunger gap'. However, rising admissions to feeding programmes from March/April suggest the intervention may be late. METHODS/DESIGN: This cluster-randomised controlled trial will compare two types of unconditional cash transfer for 'very poor' households in 'vulnerable' villages defined and identified by the implementing organisation. 3,500 children (6-59 months) and 2,500 women (15-49 years) will be recruited exhaustively from households targeted for cash and from a random sample of non-recipient households in 40 villages in Tahoua district. Clusters of villages with a common cash distribution point will be assigned to either a control group which will receive the standard intervention (n = 10), or a modified intervention group (n = 10). The standard intervention is 32,500 FCFA/month for 4 months, June to September, given cash-in-hand to female representatives of 'very poor' households. The modified intervention is 21,500 FCFA/month for 5 months, April, May, July, August, September, and 22,500 FCFA in June, providing the same total amount. In both arms the recipient women attend an education session, women and children are screened and referred for acute malnutrition treatment, and the households receive nutrition supplements for children 6-23 months and pregnant and lactating women. The trial will evaluate whether the modified unconditional cash transfer leads to a reduction in acute malnutrition among children 6-59 months old compared to the standard intervention. The sample size provides power to detect a 5 percentage point difference in prevalence of acute malnutrition between trial arms. Quantitative and qualitative process evaluation data will be prospectively collected and programme costs will be collected and cost-effectiveness ratios calculated. DISCUSSION: This randomised study design with a concurrent process evaluation will provide evidence on the effectiveness and cost-effectiveness of earlier initiation of seasonal unconditional cash transfer for the prevention of acute malnutrition, which will be generalisable to similar humanitarian situations. TRIAL REGISTRATION: ISRCTN25360839 , registered March 19, 2015
Comparing alkylresorcinols and mammalian lignans as biomarkers of wholegrain wheat or wholegrain rye intake in a dose-response intervention trial: the Grain Mark Study
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Volumetric radioassay of lead bricks being considered for unrestricted release
The hardware, software, and a protocol have been developed for the screening of lead bricks for free release or recycle from the Idaho National Engineering Laboratory. The procedure for measuring the background from a sampling of ``clean`` lead bricks and for deducing the decision limits (in pCi/g) have been developed. At the decision limit, a radioactive lead brick would be detected with 95% confidence if it were present. The total and peak efficiencies of a 2.54-cm diameter {times} 2.54-cm high NaI(Tl) scintillation detector for the counting geometry of the present study were measured with a mixed radionuclide standard and calculated with a Monte Carlo program, CYLTRAN. The deduced decision limit for the counting conditions of the present study were 0.0588 pCi/g by analyzing the entire spectrum and 0.256 pCi/g by analyzing the 661-keV peak region for a 900-second count
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