Hybrid capillary-inserted microfluidic device for sheathless particle focusing and separation in viscoelastic flow

A novel microfluidic device which consists of two stages for particle focusing and separation using a viscoelastic fluid has been developed. A circular capillary tube was used for three-dimensional particle pre-alignment before the separation process, which was inserted in a polydimethylsiloxane microchannel. Particles with diameters of 5 and 10 μm were focused at the centerline in the capillary tube, and the location of particles was initialized at the first bifurcation. Then, 5 and 10 μm particles were successfully separated in the expansion region based on size-dependent lateral migration, with ∼99% separation efficiency. The proposed device was further applied to separation of MCF-7 cells from leukocytes. Based on the cell size distribution, an approximate size cutoff for separation was determined to be 16 μm. At 200 μl/min, 94% of MCF-7 cells were separated with the purity of ∼97%. According to the trypan blue exclusion assay, high viability (∼90%) could be achieved for the separated MCF-7 cells. The use of a commercially available capillary tube enables the device to be highly versatile in dealing with particles in a wide size range by using capillary tubes with different inner diameters.     

MINNESOTA COMMUNITY COLLEGE FACULTY ACTIVITIES AND ATTITUDES, 1956–1980

A six‐page questionnaire sent in 1980 to a 25% random sample of teachers in Minnesota's 18 public community colleges provides information that is compared with similar information collected in 1956 and 1968. The nature and extent of professional activities, sources of satisfaction and dissatisfaction with careers, attitudes toward collective bargaining, and some demographic variables of Minnesota community college teachers are described and compared.

Minnesota community college faculty members in 1980 were generally contented, as they were in 1956 and 1968. In all periods they spent most of their time on teaching‐related activities. Although the proportion involved in consulting with schools, business, and industry has doubled in the past 12 years, faculty involvement in off‐campus services is still limited. Research and scholarly writing is not a function of most of the faculty. About three‐fourths of the respondents supported collective bargaining in 1980. The most serious source of dissatisfaction, reported by 40% of the respondents in 1980 was inadequate salary. The chief source of satisfaction reported in all three periods was the opportunity to help college‐age students learn and develop. Implications of the results for a re‐examination of community college functions are discussed.

The pecking order in this state does not reflect the major contribution of this system to higher education. Working conditions, particularly in terms of load and support services are primitive. Financial rewards, the status and extra income of consulting fees are severely limited. I can no longer afford five percent salary increases and twenty percent inflation. I am currently looking for a position in private industry, which seems to have the resources education does not. (Sociology instructor)

I cannot remember a profession/job that could be more personally rewarding, spiritually constructive or totally satisfying as college teaching. (English/history instructor)     

Analysing peer feedback in asynchronous online discussions: A case study

Education and Information Technologies - Peer feedback is referred to as comments provided by one student to another with the intention to aid their peers’ progress in learning. The responses...     

The developmental directions and tasks of the school based curriculum management system in Korea

The purpose of this paper is to inquire into the developmental directions and tasks of the School Based Curriculum Management(SBCM) system. The concept of the School Based Curriculum Management can be considered as a subsystem to School Based Management. The logics behind the SBCM system are autonomy, accountability, effectiveness, creativity, professionalism, and participation. The developmental directions of SBCM are to establish and implement the highly autonomous and participative SBCM, the diverse creative SBCM, the highly accountable SBCM, and the professional SBCM. The developmental tasks of SBCM suggested in this study are to establish the School Based Staff Development system, to practice the evaluation system that can control the quality of SBCM, to be managed by a strategic-layer management system, and to constitute the committee of school curriculum.     

Controlled choice assignments: A new and more effective approach to school desegregation

The authors argue that conventional mandatory and voluntary school desegregation techniques have failed to provide minority students with maximum feasible relief from invidious discrimination because they do not redress the root causes of segregation. They demonstrate that residential-based student assignment plans as well as plans that give students limited access to a few educationally enriched magnet schools are not asymmetrical remedies to wrongful segregation and thus work to perpetuate the racial and social inequities that they purport to correct. The authors offer an alternative approach to school desegregation—controlled choice—that operates independently from residential housing patterns and which explicitly seeks to maximize personal choice within a racially unitary, equitable, and educationally enhanced system of public schooling. Controlled choice was originally pioneered in Cambridge, Mass. during the early 1980s and has recently been adopted in Little Rock, Ark., and Fall River, Mass. The policy is also being actively reviewed by several of the nation's largest school districts including Seattle, Memphis, and Boston.