For-Profit Higher Education and Community Colleges

The recent growth of for-profit educational providers has been one of the most watched trends in higher education (Blumenstyk, 2000; Burd, 1998; Selingo, 1999; Strosnider, 1998). Despite the widespread attention, surprisingly little concrete information exists about the for-profit phenomenon. Although the for-profit sector is not the only source of new competition in higher education, the highly publicized growth of some for-profit institutions has generated increasing anxiety among both private non-profit and public colleges and universities. To develop a better understanding of how these institutions compare to public community colleges with respect to their students and programs, the Community College Research Center joined with the National Center for Postsecondary Improvement (NCPI) to conduct a two-year study. The objective was to determine whether these two types of institutions are competitive or complementary and how community colleges have responded to the growth of the for-profits

Facilitating Student Learning Through Contextualization

This Brief, based on a longer review that considers the hypothesis that low-skilled students can learn more effectively and advance to college-level programs more readily through contextualization of basic skills instruction, presents two forms of contextualization that have been studied: “contextualized“ and “integrated“ instruction. There is more descriptive work on the contextualization of basic skills than studies with student outcome data. In addition, many studies with quantitative evidence on the effectiveness of contextualization have methodological flaws that limit conclusions. Further, only a small number of studies are with college students. However, despite these problems, contextualization seems to be a promising direction for accelerating the progress of academically underprepared college students. The method of contextualization is grounded in a conceptual framework relating to the transfer of skill and student motivation; practitioners who use it observe positive results, and the available quantitative evidence indicates that it has the potential to increase achievement

Comprehensive study of the CuF<inf>2</inf> conversion reaction mechanism in a lithium ion battery

Conversion materials for lithium ion batteries have recently attracted considerable attention due to their exceptional specific capacities. Some metal fluorides, such as CuF2, are promising candidates for cathode materials owing to their high operating potential, which stems from the high electronegativity of fluorine. However, the high ionicity of the metal–fluorine bond leads to a large band gap that renders these materials poor electronic conductors. Nanosizing the active material and embedding it within a conductive matrix such as carbon can greatly improve its electrochemical performance. In contrast to other fluorides, such as FeF2 and NiF2, good capacity retention has not, however, been achieved for CuF2. The reaction mechanisms that occur in the first and subsequent cycles and the reasons for the poor charge performance of CuF2 are studied in this paper via a variety of characterization methods. In situ pair distribution function analysis clearly shows CuF2 conversion in the first discharge. However, few structural changes are seen in the following charge and subsequent cycles. Cyclic voltammetry results, in combination with in situ X-ray absorption near edge structure and ex situ nuclear magnetic resonance spectroscopy, indicate that Cu dissolution is associated with the consumption of the LiF phase, which occurs during the first charge via the formation of a Cu1+ intermediate. The dissolution process consequently prevents Cu and LiF from transforming back to CuF2. Such side reactions result in negligible capacity in subsequent cycles and make this material challenging to use in a rechargeable battery.We acknowledge the funding from the U.S. DOE BES via funding to the EFRC NECCES, an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences under Award Number DE-SC0001294 (support for Rosa Robert and Lin-Shu Du) and EPSRC via the “nanoionics” programme grant (support for Xiao Hua). Use of the National Synchrotron Light Source (NSLS), Brookhaven National Laboratory (BNL), was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886. Use of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, was supported by the U.S. DOE under Contract No. DE-AC02-06CH11357.This is the final published version of the article. It first appeared at http://pubs.acs.org/doi/abs/10.1021/jp503902z and is posted here under the terms of ACS's Editors' Choice scheme (http://pubs.acs.org/page/policy/authorchoice_termsofuse.html)

Unlocking the potential of weberite-type metal fluorides in electrochemical energy storage

Sodium-ion batteries (NIBs) are a front-runner among the alternative battery technologies suggested for substituting the state-of-the-art lithium-ion batteries (LIBs). The specific energy of Na-ion batteries is significantly lower than that of LIBs, which is mainly due to the lower operating potentials and higher molecular weight of sodium insertion cathode materials. To compete with the high energy density of LIBs, high voltage cathode materials are required for NIBs. Here we report a theoretical investigation on weberite-type sodium metal fluorides (SMFs), a new class of high voltage and high energy density materials which are so far unexplored as cathode materials for NIBs. The weberite structure type is highly favorable for sodium-containing transition metal fluorides, with a large variety of transition metal combinations (M, M’) adopting the corresponding Na2MM’F7 structure. A series of known and hypothetical compounds with weberite-type structure were computationally investigated to evaluate their potential as cathode materials for NIBs. Weberite-type SMFs show two-dimensional pathways for Na+ diffusion with surprisingly low activation barriers. The high energy density combined with low diffusion barriers for Na+ makes this type of compounds promising candidates for cathode materials in NIBs

Inflammatory cell-mediated tumour progression and minisatellite mutation correlate with the decrease of antioxidative enzymes in murine fibrosarcoma cells

We isolated six clones of weakly tumorigenic fibrosarcoma (QR) from the tumorigenic clone BMT-11 cl-9. The QR clones were unable to grow in normal C57BL/6 mice when injected s.c. (1 × 105 cells). However, they formed aggressive tumours upon co-implantation with a ‘foreign body’, i.e. a gelatin sponge, and the rate of tumour take ranged from 8% to 58% among QR clones. The enhanced tumorigenicity was due to host cell-mediated reaction to the gelatin sponge (inflammation). Immunoblot analysis and enzyme activity assay revealed a significant inverse correlation between the frequencies of tumour formation by QR clones and the levels of manganese superoxide dismutase (Mn-SOD, P<0.005) and glutathione peroxidase (GPχ, P<0.01) in the respective tumour clones. Electron spin resonance (ESR) revealed that superoxide-scavenging ability of cell lysates of the QR clone with high level of Mn-SOD was significantly higher than that with low level of the antioxidative enzyme in the presence of potassium cyanide, an inhibitor for copper–zinc superoxide dismutase (CuZn-SOD) (P<0.001). Minisatellite mutation (MSM) induced by the inflammatory cells in tumour cells were investigated by DNA fingerprint analysis after QR clones had been co-cultured with gelatin-sponge-reactive cells. The MSM rate was significantly higher in the subclones with low levels of Mn-SOD and GPχ (P<0.05) than in the subclones with high levels of both enzymes. The MSM of the subclones with low levels of both enzymes was inhibited in the presence of mannitol, a hydroxyl radical scavenger. The content of 8-hydroxydeoxyguanosine (8-OHdG) by which the cellular DNA damage caused by active oxygen species can be assessed was significantly low in the tumours arising from the QR clone with high levels of Mn-SOD and GPχ even if the clone had been co-implanted with gelatin sponge, compared with the arising tumour from the QR clone with low levels of those antioxidative enzymes (P<0.001). In contrast, CuZn-SOD and catalase levels in the six QR clones did not have any correlation with tumour progression parameters. These results suggest that tumour progression is accelerated by inflammation-induced active oxygen species particularly accompanied with declined levels of intracellular antioxidative enzymes in tumour cells. © 1999 Cancer Research Campaig

For-Profit Higher Education and Community Colleges

This report addresses contemporary concerns about the competitive threat from for-profit educational institutions, contrasts national data on for-profits with national data on private non-profit and public post-secondary institutions, and examines case study data comparing a for-profit chain to three public community colleges located near branches of the chain. As a group, the for-profits are concentrated in a limited number of business and technical fields. Although they may compete with community colleges in those specific areas, the small size of the for-profit sector will limit the overall competitive effect. Moreover, some of the four-year for-profit institutions target upper division students and actively recruit community college graduates, so in this sense, these institutions are complements rather than competitors to community colleges. The authors found important differences between the two types of institutions and the community colleges may find lessons in for-profit institutions' emphasis on customer service, extensive support for employment placement, and degree completion rate

Ten years experience with a novel modification of plastibell circumcision

Background: Plastibell device is a satisfactory method of circumcision in infants. However the most common post-operative complication was bleeding (especially from the frenulum site). As a result, we introduce a novel modification of the device to prevent this complication.Patients and Methods: A prospective comparative study of Plastibell circumcision in infants up to the age of 12 months was conducted, using conventional Plastibell device and modified Plastibell device circumcision.In The first group (1000 infants), circumcision was performed with conventional Plastibell device while in the second group (4500 infants), circumcision was done with modified Plastibell device.Results: The mean age was 8 weeks. The mean operating time were 8.5 min and 5.9 min for conventional Plastibell ring and modified Plastibell device circumcision respectively. The most common postoperative  complication in first groups was bleeding. Conclusion: This modified Plastibell device, prevents the most series complication of bleeding. It is fast and ensures excellent cosmoses compared with the standard Plastibell template circumcision. Also it is easyto perform and allows the paediatric surgeon to achieve consistently excellent cosmetic results. Moreover, the shorter operating time makes circumcision by the modified Plastibell device a more practical method. Thetechnique will be described in detail.Key words: Circumcision, Plastibell, Childre

Investigation of Physical and Electrochemical Properties of β‑Ta_<i>x</i>Nb_1–<i>x</i>PO₅ as an Electrode Material for Lithium Batteries

The effect of intrinsic phase transitions and substitutions on the structural and electrochemical properties of monoclinic β-NbPO₅ as an electrode material for lithium or lithium-ion batteries is explored for the first time. Isolation of lower voltage phase transitions of the pure β-NbPO₅ was found to be highly effective in improving the long-term cycling stability of the material. An analogous impact to cycling stability was identified through the use of effective solid solutions based on cations such as Ta⁵⁺. Resulting materials exhibited excellent cycling stability, exceptionally low first cycle irreversible loss, and excellent 20C rate capability without the need for carbonaceous nanocomposites