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1.
Research has consistently found acute mental health treatment disparities among Asian Americans. One proposed reason for the underutilization of mental health services by Asian Americans is that available services are not culturally competent. This exploratory study presents qualitative data gathered from interviews with professional counselors who serve Asian American clients. Findings revealed significant barriers to counseling due to cultural stigma and shame, suppression of emotions, and communication gaps between clients and counselors. In response, clinicians frequently made adjustments to therapeutic approaches to accommodate the cultural beliefs and practices of clients and families. Implications for practice and research are discussed.  相似文献   
2.
Research Findings: This qualitative study explored the process through which a small group of preservice early childhood teachers engaged in primary caregiving as a framework for learning about early care and education with infants during an infant practicum course at a university-affiliated early childhood center in the United States. Based on multiple data sources, findings revealed that the participants found the primary care system to be beneficial to both infants and teachers. The student teachers gained a better understanding of the uniqueness of the infancy period, experienced the emotional rewards of a special relationship with an infant, and learned to provide individualized and relationship-based infant care and education, while the infants received the benefits of this care. The integration of hands-on practice enacting a primary care system in a responsive infant room, ongoing supervision, and a theory-to-practice seminar created an effective professional learning process for the student teachers, which helped them to grow as both infant teachers and early childhood professionals. Practice or Policy: These findings are a 1st step toward looking more deeply at 1 strategy as a promising practice for the future, offering implications for early childhood teacher education and new insight to the field.  相似文献   
3.
This qualitative study explores how working with infants changed pre‐service early childhood students’ thinking about important aspects of early childhood education. Through a qualitative analysis of four pre‐service early childhood students’ weekly dialogue journals during a required, one‐semester infant practicum, the authors discovered how the course provided a context for challenging students’ previously held notions about early childhood teaching and learning. Their findings showed that infants’ ways of being were a powerful influence on pre‐service early childhood students’ sense of themselves as teachers and emphasized the value of hands‐on experiences with infants as an important component of early childhood professional preparation.  相似文献   
4.
Anchored in national longitudinal data analyzed through hierarchical linear and non-linear modeling, this study found that African-American students have a similar probability of obtaining a BA degree whether they attended a historically Black college or university (HBCU) or a historically White college or university (HWCU). Among African-Americans, females are more likely to obtain a baccalaureate degree than males. Especially given that HBCUs are significantly underfunded relative to HWCUs, the findings of this study lend support to the proposition that HBCUs contribute significantly to higher education in this country and merit strong support from both the public and private sectors. This paper was presented at the American Education Research Association Conference in April 2005.  相似文献   
5.
This study assessed the effects of cues of family history as a risk factor in direct-to-consumer advertisements. An experiment with a sample of 395 adults found significant impacts of familial risk cues on self-efficacy and behavioral intentions. Specifically, familial risk cues strengthened both intention to engage in healthy lifestyles and intention to seek advertised medications, partly through enhanced efficacy. Effects on perceived genetic risk for health conditions or belief in genetic determinism were not found. The findings suggest that familial risk cues incorporated in pharmaceutical appeals can enhance behavioral intentions in response to risk, without increasing a sense of fatalism. Theoretical and practical implications of the study are discussed.  相似文献   
6.
Research in Higher Education - Using large-scale longitudinal data, this study sought to examine factors influencing two important student development outcomes in students with disabilities...  相似文献   
7.
The selective cell separation is a critical step in fundamental life sciences, translational medicine, biotechnology, and energy harvesting. Conventional cell separation methods are fluorescent activated cell sorting and magnetic-activated cell sorting based on fluorescent probes and magnetic particles on cell surfaces. Label-free cell separation methods such as Raman-activated cell sorting, electro-physiologically activated cell sorting, dielectric-activated cell sorting, or inertial microfluidic cell sorting are, however, limited when separating cells of the same kind or cells with similar sizes and dielectric properties, as well as similar electrophysiological phenotypes. Here we report a label-free density difference amplification-based cell sorting (dDACS) without using any external optical, magnetic, electrical forces, or fluidic activations. The conceptual microfluidic design consists of an inlet, hydraulic jump cavity, and multiple outlets. Incoming particles experience gravity, buoyancy, and drag forces in the separation chamber. The height and distance that each particle can reach in the chamber are different and depend on its density, thus allowing for the separation of particles into multiple outlets. The separation behavior of the particles, based on the ratio of the channel heights of the inlet and chamber and Reynolds number has been systematically studied. Numerical simulation reveals that the difference between the heights of only lighter particles with densities close to that of water increases with increasing the ratio of the channel heights, while decreasing Reynolds number can amplify the difference in the heights between the particles considered irrespective of their densities.Separating specific cells from heterogeneous or homogeneous mixtures has been considered as a key step in a wide variety of applications ranging from biomedicine to energy harvesting. For example, the separation and sorting of rare circulating tumor cells (CTCs) from whole blood has gained significant importance in the potential diagnosis and treatment of metastatic cancers.1,2 Similarly, malaria detection relies on the collection of infected red blood cells (RBCs) from whole blood.3,4 In addition, the selective separation of lipid-rich microalgae from homogeneous mixtures of microalgae is a promising technique in biomass conversion.5To date, conventional cell separation can be done by labelling cells with biomolecules to induce differences in physical properties. For instance, in a fluorescence-activated cell sorter (FACS), cells to be separated are labelled with antibodies or aptamers with fluorescent molecules, and then sorted by applying an electrical potential.6,7 Similarly, magnetic-activated cell sorter (MACS) uses magnetic.8,9 Alternatively, label-free cell separation methods have exploited inherent differences in the physical properties (e.g., size and dielectric properties) of different kinds of cells. For example, acoustophoresis forces particles larger than a desired size to move into the center of a fluidic channel by using ultrasonic standing waves.10–12 Inertial microfluidics takes advantage of curved fluidic channels in order to amplify the size differences between particles.13,14 Mass-dependent separation of particles based on gravity and hydrodynamic flow was also reported.15 Particles with different dielectric properties can also be sorted by dielectrophoresis which induces the movement of polarizable particles.16–18The disadvantage of these methods, however, is that they require external forces and labels that may cause unexpected damage to biological cells.19–21 More importantly, most methods are limited in separating cells of the same kind or cells with similar sizes and dielectric properties.Here we designed a novel, label-free density difference amplification-based cell sorting (dDACS) that allows the separation of particles with the same size and charge by exploiting subtle differences in density without the use of external forces. Figure 1(a) illustrates the proposed microfluidic model and its underlying mechanism. The conceptual microfluidic system consists of an inlet, a separation chamber (hydraulic jump cavity), and multiple outlets. Particles entering through the inlet experience gravity (FG), buoyancy (FB), and drag (FD) forces in the separation chamber. The net force acting on the particles can be described as FFGFBFD.(1)As particles enter the separation chamber (i.e., hydraulic jump cavity), FD acting on the particles changes its direction along the streamline. The particles experience additional forces in the y direction due to large tangential angle (Fig. 1(b)). For lighter particles, whose densities are close to that of the surrounding water, FD becomes comparable to FG (i.e., in the y direction), while the net force for heavier particles is less affected by this additional contribution of FD due to a large FG. As a result, the height (H) and distance (D) that each particle can travel are different depending on its density. The difference in the maximum height (ΔHmax) between two particles with different density (ρp1 and ρp2) can be further approximated as ΔHmax(vyp0)2(vyfvyp0),(ρp1ρp2),(2)where vyp0 and vyf represent the velocity of particle and fluid along the y direction at the entrance of hydraulic jump cavity, respectively.Open in a separate windowFIG. 1.Schematic illustration of label-free density difference amplification-based cell sorting (dDACS), which exploits differences in the densities (ρ1 > ρ2) of particles with similar diameters (d) and charge. (a) The conceptual microfluidic design consists of an inlet, a separation chamber (hydraulic jump cavity), and multiple outlets. Incoming particles experience gravity (FG), buoyancy (FB), and drag (FD) forces in the separation chamber, and depending on their densities, the height (H) and distance (D) that each particle is able to reach will be different, allowing the particles to be separated into multiple outlets. (b) Possible microfluidic channel configurations for density-based separation: Uniform channel height (left), gradual channel expansion (middle), and hydraulic jump cavity with sudden channel expansion (right). The height difference between particles with different densities can be amplified by the sudden channel expansion compared to the other two cases due to the relatively large tangential angle, θ of FD. (|θ1|≪ |θ2|) (see Fig. S1 in the supplementary material22).In comparison with the other two cases (Fig. 1(b) uniform channel height and gradual channel expansion), the height difference between the particles with different densities can be amplified by the sudden channel expansion in the hydraulic jump cavity due to relatively large tangential angle (see supplementary material22). Therefore, the particles can be separated through the multiple outlets, depending on their height and distance.In order to analyze the separation behavior of particles in the chamber according to differences in their densities, H and D are systematically investigated. The numerical simulations are performed using a commercial CFD software (CFX 14.0; ANSYS 14.0; ANSYS, Inc.). Particles with the same density may have different trajectories in the separation chamber depending on their inlet positions (Fig. 2(a)). Prior to this investigation, the maximum height (Hmax) and distance (Dmax) for each particle are compared by examining H and D of 100 identical particles at different inlet positions since the inlet position of particles could be controlled.20 Fig. 2(b) shows Hmax and Dmax of particles with respect to density at a fixed Reynolds number (Re = 0.1). Note that Reynolds number is defined as Re = ρfvfDh/μ, where ρf, vf, Dh, μ are density of fluid, velocity of the fluid, hydraulic diameter of a channel, and dynamic viscosity of the fluid, respectively. The hydraulic diameter in the Reynolds number is determined with the inlet channel. Particle densities in the range of 1.1 to 2.0 g/cm3 are chosen with the increase of 0.1 g/cm3. These values are quite reasonable in that the densities of many microorganisms such as microalgae are typically within this range and their densities can be varied by 0.2 g/m3 depending on their cellular context.23 The lighter particles travel with a higher Hmax, and longer Dmax. With the separation chamber, the height difference between particles with densities of 1.1 and 1.2 g/cm3 can be amplified by about 10 times as compared to that in a channel without the chamber, judging from the position where the 1.1 g/cm3 particle reaches its Hmax.Open in a separate windowFIG. 2.Microfluidic particle separation with respect to Reynolds number (Re). (a) Trajectories in the separation chamber of a hundred particles with the same density starting from inlet positions chosen arbitrarily in order to investigate the effect of the inlet positions on the maxima of the height (Hmax) and distance (Dmax) prior to further simulation. (b) Representative trajectories of particles having different densities from 1.1 to 2.0 g/cm3. (c) The maximum height (Hmax) of each particle with respect to Re. (d) Representative maximum distance (Dmax) of each particle at Re = 0.1. (Left) Streamline of fluid and representative trajectories of particles with densities of 1.1 and 2.0 g/cm3 in the separation chamber at Re = 0.1 (right).In Fig. 2(c), the values for Hmax of particles with respect to Reynolds number (Re) are presented. Since in our study, the maximum height (Hmax) and distance (Dmax) for each particle were compared by examining H and D of 100 identical particles that are randomly distributed in the channel (throughout all figures), there is little variation in Hmax and Dmax between each simulation. However, the standard deviation between each simulation is quite small and can be negligible. The Hmax values particles at Re = 0.5 with densities of 1.1 g/cm3 and 1.2 g/cm3 are 2.21 × 103 μm and 2.17 × 103 μm, respectively. The difference between Hmax of different particles, ΔHmax, increases with decreasing Re. For example, ΔHmax between particles with densities of 1.1 and 2.0 g/cm3 becomes 0.26 × 103 μm at Re = 1.0, but increases to 1.38 × 103 μm as Re decreases to 0.1. As Re increases (velocity of fluid increases), the relative velocity in the y direction between the fluid and the particle increases resulting in increasing of FD in the y direction since the velocity of particle in the y direction is very small at the entrance of the separation chamber. Thus, contribution of FD becomes comparable to the net force in the y direction. As a result, most of the particles even in the case of heavier ones travel quite similarly with the streamline, and ΔHmax subsequently decreases. On the other hand, as Re decreases, the contribution of FG becomes dominant due to the decrease of FD in the y direction. Consequently, the particles start to cross downwards streamlines as the density of the particles increases and Hmax gradually decreases. In addition, irrespective of their densities, ΔHmax of the particles increases with decreasing Re.Fig. 2(d) shows Dmax with respect to the density of the particles (left). Different densities of particles show different trajectories due to the relative contribution of FD to the net force in the y direction depending on the particle density (right). At Re = 0.1, Dmax of particles with densities of 1.1 cm3 and 1.2 g/cm3 are 2.91 × 104 μm and 1.43 × 104 μm, respectively. As the density of a particle increases, its Dmax dramatically decreases. The difference in Dmax between particles with densities of 1.1 and 1.2 g/cm3 is 1.48 × 104 μm, and 0.0037 × 104 μm for particles with densities of 1.9 and 2.0 g/cm3. The effect of FD is stronger compared to that of FG on lighter particles. Thus, lighter particles travel quite similarly with the streamline and finally have a large Dmax. On the other hand, heavier particles where effect of FG is stronger compared to that of FD cross downwards streamlines and finally have a small Dmax.Next, in order to investigate the separation behavior of particles with respect to the geometry of the microfluidic device, the effect of the ratio of the height of the separation chamber (hc) to the inlet (hi) on Hmax is investigated as shown in Fig. Fig.3.3. Interestingly, Hmax of particles with density of 1.1 g/cm3 increases from 1.93 × 103 μm to 6.48 × 103 μm while that of particles with density of 1.9 g/cm3 slightly changes from 0.70 × 103 μm to 0.73 × 103 μm as hc/hi increases from 5 to 20.Open in a separate windowFIG. 3.Microfluidic particle separation with respect to the ratio of the height of the inlet (hi) to the separation chamber (hc).This result can be attributed to two effects: (1) the change in the streamline and (2) the relative contribution of drag force to the net force depending on the density. With increasing hc/hi, dramatic increase in Hmax for lighter particles is because the streamline for the lighter ones experiences more vertical displacement in the separation chamber and the contribution of FD to the net force acting on the lighter one is more significant (see Fig. S2 in the supplementary material22).Based on this approach, we propose a microfluidic device for the selective separation of the lightest particle. Fig. 4(a) shows one unit (with three outlets) of the proposed microfluidic device that can be connected in series. The ratio of channel heights (hc/hi) is set to 20, and the particle densities are in the range of 1.1 ∼ 1.5 g/m3. Fig. 4(b) shows the representative separation behavior of the particles. A portion of the lightest particles (1.1 g/cm3) is selectively separated into the upper and middle outlets, while remaining light particles together with four other heavier particles with densities in the range of 1.2 to 1.5 g/cm3 leave through the lowest outlet. With a single operation of this unit, 40% of the lightest particles are recovered. In addition, the yield increases with increasing number of cycles (Fig. 4(c)).Open in a separate windowFIG. 4.(a) One unit of the proposed microfluidic device for the selective separation of the lightest particle based on the simulation results. Particles are separated into two outlets based on differences in both the height and distance travelled stemming from differences in density. (b) Representative separation behavior of particles observed in the device. (c) The yield of the lightest particle (1.1 g/cm3) with the proposed microfluidic device according to the number of cycles (i.e., this unit is assumed to be connected in series).In summary, we have demonstrated a label-free microfluidic system for the separation of particles according to subtle differences in their densities without external forces. Our microfluidic design consists simply of an inlet, a separation chamber, and multiple outlets. When entering the separation chamber, the particles experience an additional drag force in the y direction, amplifying the difference in both the height and the distance that the particles with different densities can travel within the chamber. At a fixed Reynolds number, with increasing particle density, Hmax decreases monotonously, and Dmax decreases dramatically. On the other hand, as Reynolds number increases, the difference between the heights of particles with different densities is attenuated. In addition, the simulation reveals that increasing the ratio of the channel heights increases the difference between the heights of particles only when their densities are close to that of the surrounding water. Based on this approach, a microfluidic device for the separation of the lightest particles has been proposed. We expect that our density-based separation design can be beneficial to the selective separation of specific microorganisms such as lipid-rich microalgae for energy harvesting application.  相似文献   
8.
This article examines the relationship between sponsored research monies and the graduation of undergraduate students at 22 public research universities. Using institutional and student characteristics for 59,982 students at these universities, we conducted chi-square, cross-tabulation, correlation, and hierarchical nonlinear modeling (HNLM) analyses to determine the relationship between our principal independent and dependent variables, and among them and other individual and institutional variables, including SAT (individual and institutional mean), gender (individual and percentage), underrepresented minority (individual and percentage), and graduate academic program rating. In contrast to a basic premise of most policymakers and academic managers, our findings suggest that an institution's sponsored research expenditures are positively related to undergraduates' graduation. We also find that mean SAT has a powerful impact on student graduation, although at the individual level gender is a more powerful correlate of graduation than is SAT score.  相似文献   
9.
Much research on risk perception and health behavior has examined cognitive dimensions of risk but not affective dimensions. To address this gap, this study examines both cognitive risk perception (perceived risk of susceptibility and severity) and affective risk perception (worry) in the context of food safety risks in East Asia. We investigate their roles in independently and jointly predicting intention to consume outbreak-associated food products, as well as mediating the influences of news exposure and attention on intention. Data from a nationwide survey in South Korea (N = 1500) lent overall support for our hypotheses in both cases of processed food from China and seafood from Japan. Our findings show: (1) both perceived risk and worry were negatively associated with food consumption intention, and the association between perceived risk and intention was stronger among those higher in worry; (2) news attention had stronger associations with perceived risk and worry than news exposure, and attention moderated the relationship between news exposure and perceived risk; and (3) perceived risk and worry mediated the associations between news use and food consumption intention. Implications and limitations of the findings are discussed.  相似文献   
10.
This study, using national surveys and multilevel models, examines the effectiveness of 4-year women-only and coeducational colleges in cultivating women students' intellectual development. No significant differential effect of attending either type of institution was discovered relative to students' critical thinking ability and analytical and problem-solving skills. Women-only colleges seem to provide neither a superior nor an inferior growth experience for female students compared with coeducational institutions. However, analyses suggest that women-only colleges have a significantly greater positive impact on development of intellectual self-confidence. Campus environment as well as college experiences of women students at women-only and coeducational colleges are discussed to explain the reasons for the differential institutional effect. Analyses also indicate that compared with female students in coeducational settings, students in women-only colleges are more likely to participate in college activities that are intellectually stimulating and cultivating.  相似文献   
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