ABSTRACT
BACKGROUND: Novice nurses, occupational and physical therapist's injury rates are alarming. OBJECTIVE: To test for differences in peak elbow flexion forces (PEFF) by profession using different forearm positions. METHODS: Entry-level RN, OT, and PT students performed 3-repetitions of standing PEFF in forearm supination, pronation, and neutral. A one-way repeated measures ANOVA determined the forearm position with the greatest PEFF. A one-way ANOVA assessed differences in PEFF between professions. The alpha level was set at p≤0.05 for all analyses. RESULTS: Thirty 30 RN, 25 OT, and 30 PT students (xâ=â23.27â+â/-3.29 yrs.) were studied. A one-way repeated measures ANOVA revealed a significant difference in PEFF between positions (F(2,168)â=â144.3, pâ<â0.0001). A significant (pâ<â0.0001) pairwise comparison revealed neutral produced the greatest (28.15â+â/-12.64âkg) and pronation the least PEFF (17.27â+â/-7.40). PEFF was significantly different between position by profession (supination: F(2,82)â=â10.14, pâ<â0.0001; pronation: F(2,82)â=â10.33, pâ<â0.0001; neutral: F(2,82)â=â13.39, pâ<â0.0001). PTs were significantly stronger than OTs and RN students in all forearm positions (pâ<â0.01). CONCLUSIONS: Neutral PEFF was greatest and PT students demonstrated greater PEFF than OT and RN students.
Subject(s)
Elbow Joint , Elbow , Forearm , Humans , Physical Therapy Modalities , Pronation , Students , SupinationABSTRACT
The problem of academic dishonesty is as old as it is widespread - dating back millennia and perpetrated by the majority of students. Attempts to promote academic integrity, by comparison, are relatively new and rare - stretching back only a few hundred years and implemented by a small fraction of schools and universities. However, the past decade has seen an increase in efforts among universities to promote academic integrity among students, particularly through the use of online courses or tutorials. Previous research has found this type of instruction to be effective in increasing students' knowledge of academic integrity and reducing their engagement in academic dishonesty. The present study contributes to this literature with a natural experiment on the effects of the Academic Integrity Course (AIC) at The University of Auckland, which became mandatory for all students in 2015. In 2012, a convenience sample of students (n = 780) had been asked to complete a survey on their perceptions of the University's academic integrity polices and their engagement in several forms of academic dishonesty over the past year. In 2017, the same procedures and survey were used to collect data from second sample of students (n = 608). After establishing measurement invariance across the two samples on all latent factors, analysis of variance revealed mixed support for the studies hypotheses. Unexpectedly, students who completed the AIC (i.e., the 2017 sample) reported: (1) significantly lower (not higher) levels of understanding, support, and effectiveness with respect to the University's academic integrity policies; (2) statistically equivalent (not higher) levels of peer disapproval of academic misconduct, and; (3) significantly higher (not lower) levels of peer engagement in academic misconduct. However, results related to participants' personal engagement in academic misconduct offered partial support for hypotheses - those who completed the AIC reported significantly lower rates of engagement on three of the eight behaviors included in the study. The implications and limitations of these findings are discussed as well as possible future directions for research.
ABSTRACT
There is often a divide between moral judgment and moral action; between what we believe we ought to do (or not do) and what we do. Knowledge of this divide is not new, and numerous theories have attempted to offer more robust accounts of ethical decision-making and moral functioning. Knowledge of widespread academic dishonesty among students is also not new, and several studies have revealed that many students report cheating despite believing it is wrong. The present study, involving cross-sectional survey data from a sample of secondary students (N = 380) in the United States, contributes to the literature on this important area of theory and research by fulfilling three broad purposes. The first purpose concerned the assessment of students' judgments related to academic dishonesty, and offered evidence for the utility of a new instrument that measures what domain (personal, conventional, or moral) students use to categorize various types of cheating behavior rather than how much they believe it to be wrong. The second purpose involved exploring the relations between domain judgments and engagement in academic dishonesty, and results provided evidence for the hypothesis that students who believed an action to be morally wrong would be less likely to report doing it. Finally, the third and most important purpose of the study involved bridging the divide between moral judgment and action of academic dishonesty by testing competing theoretical models of moral functioning. Results indicated that the data demonstrated the best fit to a modified version of the hypothesized four-component model, whereby self-regulation (in the form of selective moral disengagement) played a significant mediating role in the relations between moral judgment and academic dishonesty, and that moral judgment also affected self-regulation indirectly through moral motivation (i.e., responsibility judgments). In brief, findings from this study offer support for the contention that moral functioning is both multi-component and effortful. Moral judgment is important, but only one of several components needed for effective moral functioning, and motivation and self-regulation play critical mediating roles in helping to bridge the divide between judgment and action.
ABSTRACT
Despite the large body of literature describing the synthesis of magnetic nanoparticles, few analytical tools are commonly used for their purification and analysis. Due to their unique physical and chemical properties, magnetic nanoparticles are appealing candidates for biomedical applications and analytical separations. Yet in the absence of methods for assessing and assuring their purity, the ultimate use of magnetic particles and heterostructures is likely to be limited. In this review, we summarize the separation techniques that have been initially used for this purpose. For magnetic nanoparticles, it is the use of an applied magnetic flux or field gradient that enables separations. Flow based techniques are combined with applied magnetic fields to give methods such as magnetic field flow fractionation and high gradient magnetic separation. Additional techniques have been explored for manipulating particles in microfluidic channels and in mesoporous membranes. Further development of these and new analytical tools for separation and analysis of colloidal particles is critically important to enable the practical use of these, particularly for medicinal purposes.
Subject(s)
Flow Injection Analysis , Magnets , Microfluidic Analytical Techniques , Nanoparticles/analysis , Colloids/chemistry , Magnetics , Membranes, Artificial , Particle Size , PorosityABSTRACT
The lack of optical isolators has limited the serial integration of components in the development of photonic integrated circuits. Isolators are inherently nonreciprocal and, as such, require nonreciprocal optical propagation. We propose a class of integrated photonic devices that make use of electrically-generated electron spin polarization in semiconductors to cause nonreciprocal TE/TM mode conversion. Active control over the non-reciprocal mode coupling rate allows for the design of electrically-controlled isolators, circulators, modulators and switches. We analyze the effects of waveguide birefringence and absorption loss as limiting factors to device performance.
ABSTRACT
Surface chemistry plays an important role in determining flux through porous media such as in the environment. In this paper diffusive flux of nanoparticles through alkylsilane modified porous alumina is measured as a model for understanding transport in porous media of differing surface chemistries. Experiments are performed as a function of particle size, pore diameter, attached hydrocarbon chain length and chain terminus, and solvent. Particle fluxes are monitored by the change in absorbance of the solution in the receiving side of a diffusion cell. In general, flux increases when the membranes are modified with alkylsilanes compared to untreated membranes, which is attributed to the hydrophobic nature of the porous membranes and differences in wettability. We find that flux decreases, in both hexane and aqueous solutions, when the hydrocarbon chain lining the interior pore wall increases in length. The rate and selectivity of transport across these membranes is related to the partition coefficient (K(p)) and the diffusion coefficient (D) of the permeating species. By conducting experiments as a function of initial particle concentration, we find that K(p)D increases with increasing particle size, is greater in alkylsilane-modified pores, and larger in hexane solution than water. The impact of the alkylsilane terminus (-CH(3), -Br, -NH(2), -COOH) on permeation in water is also examined. In water, the highest K(p)D is observed when the membranes are modified with carboxylic acid terminated silanes and lowest with amine terminated silanes as a result of electrostatic effects during translocation.
ABSTRACT
Differential magnetic catch and release (DMCR) has been used as a method for the purification and separation of magnetic nanoparticles. DMCR separates nanoparticles in the mobile phase by magnetic trapping of magnetic nanoparticles against the wall of an open tubular capillary wrapped between two narrowly spaced electromagnetic poles. Using Au and CoFe(2)O(4) nanoparticles as model systems, the loading capacity of the 250 µm diameter capillary is determined to be â¼130 µg, and is scalable to higher quantities with larger bore capillary. Peak resolution in DMCR is externally controlled by selection of the release time (R(t)) at which the magnetic flux density is removed, however, longer capture times are shown to reduce the capture yield. In addition, the magnetic nanoparticle capture yields are observed to depend on the nanoparticle diameter, mobile phase viscosity and velocity, and applied magnetic flux. Using these optimized parameters, three samples of CoFe(2)O(4) nanoparticles whose diameters are different by less than 10 nm are separated with excellent resolution and capture yield, demonstrating the capability of DMCR for separation and purification of magnetic nanoparticles.
Subject(s)
Magnetite Nanoparticles/chemistry , Cobalt/chemistry , Ferrous Compounds/chemistry , Gold/chemistry , Magnetite Nanoparticles/ultrastructure , Particle SizeABSTRACT
Magnetic nanoparticles uniquely combine superparamagnetic behavior with dimensions that are smaller than or the same size as molecular analytes. The integration of magnetic nanoparticles with analytical methods has opened new avenues for sensing, purification, and quantitative analysis. Applied magnetic fields can be used to control the motion and properties of magnetic nanoparticles; in analytical chemistry, use of magnetic fields provides methods for manipulating and analyzing species at the molecular level. In this review, we describe applications of magnetic nanoparticles to analyte handling, chemical sensors, and imaging techniques.
ABSTRACT
Computed tomographic (CT) scanning technology now employs up to 320 detector rows of 0.5-mm width and allows rapid acquisition of isotropic volume datasets over the entire body. Data from a single CT acquisition can be reconstructed into image series that would formerly have required multiple acquisitions. Small isotropic voxels permit scan parameters to be general while reconstruction algorithms remain specific to anatomy. While this results in more efficient operation in the Emergency Department, it necessitates new ways of displaying, interpreting, and archiving the information. Critical decisions include how much of the patient to scan and how to time contrast injections when imaging multiple organs. These choices must be made in light of dose considerations to the patient and the general population of patients. The technical basis of high-density CT scanning is discussed, including detector configurations and reconstruction techniques. Volumetric scanning in the Emergency Department can improve patient care but requires a change of technical habits.
Subject(s)
Emergency Service, Hospital , Tomography, X-Ray Computed/statistics & numerical data , Algorithms , Contrast Media , Decision Making , Humans , Quality Assurance, Health Care , Radiation Dosage , Radiographic Image Interpretation, Computer-Assisted , Radiology Information Systems/organization & administration , Time Factors , Tomography, X-Ray Computed/methodsABSTRACT
Measurement of transport of nanometer scale particles through porous media is important to begin to understand the potential environmental impacts of nanomaterials. Using a diffusion cell with two compartments separated by either a porous alumina or polycarbonate membrane as a model system, diffusive flux through mesoporous materials is examined. Experiments are performed as a function of particle size, pore diameter, and solvent, and the particle fluxes are monitored by the change in absorbance of the solution in the receiving cell. Using the measured extinction coefficient and change in absorbance of the solution as a function of time, the fluxes of 3, 8, and 14 nm diameter CoFe(2)O(4) particles are determined as they are translocated across pores with diameters 30, 50, 100, and 200 nm in hexane and aqueous solutions. In general, flux decreases with increasing particle size and increases with pore diameter. We find that fluxes are faster in aqueous solutions than in hexane, which is attributed to the hydrophilic nature of the porous membranes and differences in wettability. The impact of an applied magnetic flux gradient, which induces magnetization and motion, on permeation is also examined. For larger membrane pore diameters, applied magnetic fluxes increase the rate of transport of 14 nm CoFe(2)O(4) particles more than that of 3 or 8 nm diameter particles, reflecting their differences in susceptibility. However, larger particles are excluded from membranes with small diameter pores, consistent with magnetic interparticle attractions that reversibly induce magnetic aggregation.
ABSTRACT
This article reports the purification and separation of magnetic nanoparticle mixtures using differential magnetic catch and release (DMCR). This method applies a variable magnetic flux orthogonal to the flow direction in an open tubular capillary to trap and controllably release magnetic nanoparticles. Magnetic moments of 8, 12, and 17 nm diameter CoFe2O4 nanoparticles are calculated using the applied magnetic flux and experimentally determined force required to trap 50% of the particle sample. Balancing the relative strengths of the drag and magnetic forces enables separation and purification of magnetic CoFe2O4 nanoparticle samples with <20 nm diameters. Samples were characterized by transmission electron microscopy to determine the average size and size dispersity of the sample population. DMCR is further demonstrated to be useful for separation of a magnetic nanoparticle mixture, resulting in samples with narrowed size distributions.
Subject(s)
Cobalt/chemistry , Ferrous Compounds/analysis , Ferrous Compounds/isolation & purification , Magnetics , Nanoparticles/analysis , Complex Mixtures/analysis , Complex Mixtures/chemistry , Complex Mixtures/isolation & purification , Ferrous Compounds/chemistry , Kinetics , Nanoparticles/chemistry , Particle SizeABSTRACT
We describe measurements of spin dynamics in the two-dimensional electron gas in GaAs/GaAlAs quantum wells. Optical techniques, including transient spin-grating spectroscopy, are used to probe the relaxation rates of spin polarization waves in the wave vector range from zero to 6x10(4) cm-1. We find that the spin polarization lifetime is maximal at a nonzero wave vector, in contrast with expectations based on ordinary spin diffusion, but in quantitative agreement with recent theories that treat diffusion in the presence of spin-orbit coupling.