3,338 research outputs found
Consensual Qualitative Research: An Update
The authors reviewed the application of consensual qualitative research (CQR) in 27 studies published since the method’s introduction to the field in 1997 by C. E. Hill, B. J. Thompson, and E. N. Williams (1997). After first describing the core components and the philosophical underpinnings of CQR, the authors examined how it has been applied in terms of the consensus process, biases, research teams, data collection, data analysis, and writing up the results and discussion sections of articles. On the basis of problems that have arisen in each of these areas, the authors made recommendations for modifications of the method. The authors concluded that CQR is a viable qualitative method and suggest several ideas for research on the method itself
Boolean versus continuous dynamics on simple two-gene modules
We investigate the dynamical behavior of simple modules composed of two genes
with two or three regulating connections. Continuous dynamics for mRNA and
protein concentrations is compared to a Boolean model for gene activity. Using
a generalized method, we study within a single framework different continuous
models and different types of regulatory functions, and establish conditions
under which the system can display stable oscillations. These conditions
concern the time scales, the degree of cooperativity of the regulating
interactions, and the signs of the interactions. Not all models that show
oscillations under Boolean dynamics can have oscillations under continuous
dynamics, and vice versa.Comment: 8 pages, 10 figure
Alabama\u27s Women in Agriculture: The Road to GAPs Harmonization and Global Addendum - Tuskegee\u27s Walmart Initiative
This paper shares challenges faced and overcome by four African American women on their 2013 journey to secure USDA’s Produce Good Agricultural Practices (GAPs) Harmonized Food Safety Standards with the Global Addendum (Global Markets Primary Production Assessments: GMPPA). Collaboration, consistent training, and technical support from the Tuskegee University Extension and Research staff, and the Small Farmers Agricultural Cooperative undergirded the preparation of the farms for GAPs Certification. The timely sharing of staff expertise and experience from commercial partners (Walmart, Purivida, C.H. Robinson, W.P. Rawls), and support from the USDA (Strike Force Initiative) were important contributors to the positive outcomes described. The outcomes elucidate the adaptability, accountability, and professionalism each participant displayed to prepare her farm for audits; maintain food safety records, and achieve GAPs certification in marketable crops.
Key Words: Socially Disadvantaged Women Farmers, Food Safety, GAPs certificatio
Viewing Preschool Disruptive Behavior Disorders and ADHD Through A Developmental Lens: What We Know & What We Need to Know
There is now little doubt that DSM-IV behavior disorders are present and identifiable during the preschool years (1,2). With only minor modifications to DSM-IV Disruptive Behavior Disorders (DBDs) and attention-deficit/hyperactivity disorder (ADHD) nosology, multiple, independent studies have shown similar prevalence rates and correlates as in older children (1). In the preschool age range, these disorders also have modest stability (3-6). It is clear that the behaviors that comprise DBDs and ADHD (e.g., noncompliance, rule-breaking, aggression, destruction of property, hyperactivity, inattention, and impulsivity) impair children’s functioning and that caregivers of young children often experience considerable difficulty in managing those who exhibit high levels of these behaviors. Increasingly, preschoolers are being referred to mental health clinics for DBDS and ADHD (7), with escalating rates of pharmacological treatments (8). Thus, the “real world” consequences of behavior disorders are substantial for young children and their families and often mark the onset of long-term developmental maladaptation that marks psychopathology (9). Concerted effort to characterize the clinical manifestations of these disorders in early childhood more precisely will maximize our ability to intervene effectively in the lives of young children affected with DBDs and ADHD and, ultimately to reduce their long-term health burden. The increasing consensus that these syndromes exist in young children also comes with growing concern that these disorders may be developmentally misspecified, particularly for young children who are not at the extremes (10). In this paper, we review the extant empirical evidence through a “developmental lens,” with an eye to analyzing how the absence of a developmental approach may hinder accurate identification. Further, we show how integrating evidence from developmental science provides useful guideposts for generating and testing a developmentally-specified nosology. Together with the plethora of work on preschool psychopathology over the past decade, this provides a strong foundation for charting a course for the next generation of more refined efforts in early childhood
Asymmetric Lineshape due to Inhomogeneous Broadening of the Crystal-Field Transitions in Mn12ac Single Crystals
The lineshape of crystal-field transitions in single crystals of Mn12ac
molecular magnets is determined by the magnetic history. The absorption lines
are symmetric and Gaussian for the non-magnetized state obtained by zero-field
cooling (zfc). In the magnetized state which is reached when the sample is
cooled in a magnetic field (fc), however, they are asymmetric even in the
absence of an external magnetic field. These observations are quantitatively
explained by inhomogeneous symmetrical (Gaussian) broadening of the
crystal-field transitions combined with a contribution of off-diagonal
components of the magnetic susceptibility to the effective magnetic
permeability.Comment: 4 pages, 3 figure
Teaching Elementary Mathematics with Educational Robotics
Current education reforms call for engaging students in learning science, technology, engineering, and mathematics (STEM) in an integrative way. This critical case study of one fourth grade teacher investigated the use of educational robots (ER) not only for teaching coding, but as an instructional support in teaching mathematical concepts. To support teachers in teaching coding in an integrative and logical manner, our team developed the Collective Argumentation Learning and Coding (CALC) approach. The CALC approach consists of three elements: choice of task, coding content, and teacher support for argumentation. After a cohort of elementary teachers completed a professional development course, we followed them into their classrooms to support and document implementation of the CALC approach. Data for this case consisted of video recordings of two lessons, a Pre-interview, and Post-interview after each lesson. Research questions included: How does an elementary teacher use the CALC approach (integrative STEM approach) to teach mathematics concepts with ER? What are the teacher’s perspectives towards teaching mathematics with ER using an integrative STEM approach? Results from this critical case provide evidence that teachers can successfully integrate ER into the mathematics curriculum without losing coherence of mathematics topics and while remaining sensitive to students’ needs
Application of relativistic scattering theory of x rays to diffraction anomalous fine structure in Cu
We apply our recent first-principles formalism of magnetic scattering of circularly polarized x rays to a single Cu crystal. We demonstrate the ability of our formalism to interpret the crystalline environment related near-edge fine structure features in the resonant x-ray scattering spectra at the Cu K absorption edge. We find good agreement between the computed and measured diffraction anomalous fine structure features of the x-ray scattering spectra
Role of dipolar and exchange interactions in the positions and widths of EPR transitions for the single-molecule magnets Fe8 and Mn12
We examine quantitatively the temperature dependence of the linewidths and
line shifts in electron paramagnetic resonance experiments on single crystals
of the single-molecule magnets Fe and Mn, at fixed frequency, with
an applied magnetic field along the easy axis. We include inter-molecular
spin-spin interactions (dipolar and exchange) and distributions in both the
uniaxial anisotropy parameter and the Land\'{e} -factor. The temperature
dependence of the linewidths and the line shifts are mainly caused by the
spin-spin interactions. For Fe and Mn, the temperature dependence of
the calculated line shifts and linewidths agrees well with the trends of the
experimental data. The linewidths for Fe reveal a stronger temperature
dependence than those for Mn, because for Mn a much wider
distribution in overshadows the temperature dependence of the spin-spin
interactions. For Fe, the line-shift analysis suggests two competing
interactions: a weak ferromagnetic exchange coupling between neighboring
molecules and a longer-ranged dipolar interaction. This result could have
implications for ordering in Fe at low temperatures.Comment: published versio
Theoretical Analysis of the "Double-q" Magnetic Structure of CeAl2
A model involving competing short-range isotropic Heisenberg interactions is
developed to explain the "double-q" magnetic structure of CeAl. For
suitably chosen interactions, terms in the Landau expansion quadratic in the
order parameters explain the condensation of incommensurate order at
wavevectors in the star of (1/2 , 1/2 , 1/2), where
is the cubic lattice constant. We show that the fourth order terms in the
Landau expansion lead to the formation of the so-called "double-q" magnetic
structure in which long-range order develops simultaneously at two
symmetry-related wavevectors, in striking agreement with the magnetic structure
determinations. Based on the value of the ordering temperature and of the
Curie-Weiss of the susceptibility, we estimate that the nearest
neighbor interaction is ferromagnetic, with K and the
next-nearest neighbor interaction is antiferromagnetic with K.
We also briefly comment on the analogous phenomenon seen in the similar system
TmS.Comment: 22 pages, 6 figure
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