1,410 research outputs found

    The Heart And Pregnancy

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    A CAJM article on the close relationship between pregnancy and heart problems.Heart disease and pregnancy are two conditions that are handled commonly by a medical practitioner, and yet it is surprising to find that the influence which one has on the other is often not clearly understood. It would seem reasonable, therefore, to review briefly current concepts on the changes in haemodynamics that occur during pregnancy and labour, and thereafter consider the effects of pregnancy on the diseased heart

    ON-FARM RESEARCH IN A DECENTRALIZED INFORMATION MODEL OR GRASSROOTS STATISTICS

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    Practical Farmers of Iowa (PFI) is an organization that seeks to provide interactive methods of relaying information through farmer-to-farmer sharing (farm field days, workshop discussions, networking) and the generation of new information. On-farm research (OFR) is an important information-generating activity of this group. PFI has shown that key to doing research on farms lies in combining practical protocols with the statistician\u27s old familiar friends - replication and randomization. We provide background on PFI and how PFI cooperators carne to using strip plots and paired comparisons to answer fundamental questions about what to do on their individual farms. We discuss the challenges faced by OFR cooperators, how those challenges are met and how the simple paired comparison t-test works for the OFR cooperator to answer that very typical experimental question posed by producers: Is alternative practice \u27b\u27 better than, worse than, or no different from my current practice \u27a\u27

    General Formalism for Evaluating the Impact of Phase Noise on Bloch Vector Rotations

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    Quantum manipulation protocols for quantum sensors and quantum computation often require many single qubit rotations. However, the impact of phase noise in the field that performs the qubit rotations is often neglected or treated only for special cases. We present a general framework for calculating the impact of phase noise on the state of a qubit, as described by its equivalent Bloch vector. The analysis applies to any Bloch vector orientation, and any rotation axis azimuthal angle for both a single pulse, and pulse sequences. Experimental examples are presented for several special cases. We apply the analysis to commonly used composite π\pi-pulse sequences: CORPSE, SCROFULOUS, and BB1, used to suppress static amplitude and detuning errors, and also to spin echo sequences. We expect the formalism presented will help guide the development and evaluation of future quantum manipulation protocols.Comment: 12 pages, 6 figures, submitted to PR

    Meaningful associations in the adolescent brain cognitive development study

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    The Adolescent Brain Cognitive Development (ABCD) Study is the largest single-cohort prospective longitudinal study of neurodevelopment and children\u27s health in the United States. A cohort of n = 11,880 children aged 9-10 years (and their parents/guardians) were recruited across 22 sites and are being followed with in-person visits on an annual basis for at least 10 years. The study approximates the US population on several key sociodemographic variables, including sex, race, ethnicity, household income, and parental education. Data collected include assessments of health, mental health, substance use, culture and environment and neurocognition, as well as geocoded exposures, structural and functional magnetic resonance imaging (MRI), and whole-genome genotyping. Here, we describe the ABCD Study aims and design, as well as issues surrounding estimation of meaningful associations using its data, including population inferences, hypothesis testing, power and precision, control of covariates, interpretation of associations, and recommended best practices for reproducible research, analytical procedures and reporting of results

    Open-front Systems

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    Dave Serfling and his family live in Preston, Minnesota, which is just north across the border from Decorah. Dave graduated from ISU in 1981 in farm operations. Serflings have a 50 sow farrow-to-finish operation and 80 cows they feed out. They also have sheep, and they own about 350 acres. They love Iowa so much, Dave\u27s wife even works in Iowa, so thanks for helping the economy. (laughter) Steve Williams and his wife live in Villisca, in Page County. Steve is a 1988 ISU business graduate. He has a total livestock operation with beef and a farrow-tofeeder pig operation. He feeds out a few. There are some interesting family ties and partnerships in Page County, and now his operation\u27s up to about 300 sows in a very productive and unique arrangement, which we\u27ll hear more about. Greg Vogel represents the ISU AG 450 Farm, which is located southwest of Ames , about a mile. This is actually a student-managed farm, and many of you are familiar with that concept that the students really manage it, for better or for worse. And they suffer all the advantages and perils of pure agriculture. Greg is the farm operator. He\u27s also an ISU grad (ag business, 1978) and finished a master\u27s in ag business in 1994. The farm is about 950 acres, and they have 200 sows out there. They run both outdoor and confmement operations. Last we\u27ll hear from my good friend, Dick Thompson. Dick and Sharon, of course, farm in Boone County. Dick and Sharon recently were recognized as the 1996 Farm Agricultural Leaders of The Year by the Des Moines Register, which was a tremendous honor for them. There farm is a little under 400 acres, they have been the driving force behind and the inspiration behind Practical Farmers of Iowa. Dick and Sharon have served as mentors for many, many farm families, not only in Iowa but nationwide. I know Dick and Sharon now have a cow-calf operation, and with their son, Rex, they have some of the facilities we\u27re talking about today, and they\u27re trying some new things in agriculture, so we\u27re pleased to have Dick here

    Proposed revision of the higher tier testing requirements for EPPO Standard PP1/170: Test methods for evaluating the side-effects of plant protection products on honeybees

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    contribution to session I  Regulatory issues Background: Regulatory evaluations for the effects of pesticides on honeybees in the EU are based on the honeybee test guidelines and risk assessment scheme of the European Plant Protection Organisation (EPPO). While this is considered to be robust and effective, it is also recognised that a continuous process of review and appropriate development is necessary. A working group of the International Commission for Plant-Bee Relationships (ICPBR) had been set up to review the current guidance set out in the EPPO PP1/170 standard for higher tier testing i.e. semi-field (cage) test and full field studies. The aim of this group was to utilise the considerable experience obtained with honey bee testing. This paper presents the working group’s proposed revision to the EPPO standard PP1/170, taking into account feedback received from the 10th ICPBR Symposium in Bucharest.Results: The primary aim of the group has been to produce guidance that is sufficiently detailed yet suitably flexible so that it enables tests to be conducted and evaluated without being too prescriptive. In particular, it recognises that higher tier testing may arise as a result of various initial concerns e.g. adult toxicity, brood effects and systemic toxicity. The guidance is designed to provide the different emphasis that is required to meet the specific requirements of individual studies. Conclusion: The revision of higher tier testing for honeybees presented in this paper is proposed as an update to the current EPPO PP1/170 standard.Keywords: honey bees, test guidelines, higher tier, semi-field (cage) tests, field tests

    Primary Structure and Catalytic Mechanism of the Epoxide Hydrolase from Agrobacterium radiobacter AD1

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    The epoxide hydrolase gene from Agrobacterium radiobacter AD1, a bacterium that is able to grow on epichlorohydrin as the sole carbon source, was cloned by means of the polymerase chain reaction with two degenerate primers based on the N-terminal and C-terminal sequences of the enzyme. The epoxide hydrolase gene coded for a protein of 294 amino acids with a molecular mass of 34 kDa. An identical epoxide hydrolase gene was cloned from chromosomal DNA of the closely related strain A. radiobacter CFZ11. The recombinant epoxide hydrolase was expressed up to 40% of the total cellular protein content in Escherichia coli BL21(DE3) and the purified enzyme had a kcat of 21 s-1 with epichlorohydrin. Amino acid sequence similarity of the epoxide hydrolase with eukaryotic epoxide hydrolases, haloalkane dehalogenase from Xanthobacter autotrophicus GJ10, and bromoperoxidase A2 from Streptomyces aureofaciens indicated that it belonged to the α/β-hydrolase fold family. This conclusion was supported by secondary structure predictions and analysis of the secondary structure with circular dichroism spectroscopy. The catalytic triad residues of epoxide hydrolase are proposed to be Asp107, His275, and Asp246. Replacement of these residues to Ala/Glu, Arg/Gln, and Ala, respectively, resulted in a dramatic loss of activity for epichlorohydrin. The reaction mechanism of epoxide hydrolase proceeds via a covalently bound ester intermediate, as was shown by single turnover experiments with the His275 → Arg mutant of epoxide hydrolase in which the ester intermediate could be trapped.

    How effective is study abroad as a pedagogical and experiential learning tool in LIS education?

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    As the conference theme implies, internationalization of LIS education is a critical part of preparing graduates for the fast-changing environments in which libraries and other cultural institutions operate. This session sponsored by the International Library Education SIG focuses on experiences and impact of study abroad programs on students and program coordinators. The fundamental question is how effective is study abroad as a pedagogical and experiential learning tool? Panelists will address that question through the lens of students and program coordinators that recently completed study abroad experiences. The panel brings together faculty coordinator of study abroad programs in selected LIS schools across the country. Where possible, faculty coordinators will bring students that completed a study abroad program to be part of the session. The panel represents diverse programs ranging from European to South American locations (Costa Rica; Italy, Ireland/United Kingdom; Germany, and South Korea). They also represent different LIS areas from archives to international LIS education. The goal of the session is to reflect on the programs, what has been learned and other lessons gleaned collectively and individually. The session will be chaired by the SIG chair who will do the introductions and provide background information to contextualize the goals of the program. Each panelist will be asked to share their experiences and what has been learned from the program and how it has enriched the learning environment in the LIS program

    Vascular adaptation to exercise in humans: Role of hemodynamic stimuli

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    On the 400th anniversary of Harvey’s Lumleian lectures, this review focuses on “hemodynamic” forces associated with the movement of blood through arteries in humans and the functional and structural adaptations that result from repeated episodic exposure to such stimuli. The late 20th century discovery that endothelial cells modify arterial tone via paracrine transduction provoked studies exploring the direct mechanical effects of blood flow and pressure on vascular function and adaptation in vivo. In this review, we address the impact of distinct hemodynamic signals that occur in response to exercise, the interrelationships between these signals, the nature of the adaptive responses that manifest under different physiological conditions, and the implications for human health. Exercise modifies blood flow, luminal shear stress, arterial pressure, and tangential wall stress, all of which can transduce changes in arterial function, diameter, and wall thickness. There are important clinical implications of the adaptation that occurs as a consequence of repeated hemodynamic stimulation associated with exercise training in humans, including impacts on atherosclerotic risk in conduit arteries, the control of blood pressure in resistance vessels, oxygen delivery and diffusion, and microvascular health. Exercise training studies have demonstrated that direct hemodynamic impacts on the health of the artery wall contribute to the well-established decrease in cardiovascular risk attributed to physical activity. © 2017 the American Physiological Society
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