Effectiveness of Anti-Bullying Policies in High Schools

This study focused on the effectiveness of anti-bullying policies in high schools from the perspectives of college students. Literature suggests that anti-bullying policies are in place nationally in high schools but implementation of these policies have been questionable. Several studies have indicated a need for more enforcement of bullying prevention efforts in high schools. This quantitative study gathered data from surveys distributed to and completed by college freshmen students, almost all of whom have had a bullying experience at least once in high school. Findings imply that participants were split in their perspective of how effective and beneficial their high school’s attempts were in implementing their anti-bullying policies. This study suggests that more research be done in order to closely and further investigate the effectiveness of anti-bullying policies in high schools

Electrodeposition of conducting polymer fibers

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2004.Includes bibliographical references (leaf 35).Conducting polymers are materials that possess the electrical conductivity of metals while still retaining the mechanical properties such as flexibility of traditional polymers. Polypyrrole (PPy) is one of the more commonly studied electrically conducting polymers due to its high conductivity and stability in ambient conditions. A one step electrochemical process for growing macroscopic conducting polymer fibers previously described in Li et al's article (Science, 1993) was used to grow PPy fibers. Based on a schematic of the electrochemical flow cell used in the electrodeposition process, a physical electrochemical flow cell was constructed. Several trials were carried out in an attempt to repeatedly grow polymer fibers. The fibers grown from successful trials were analyzed and characterized by qualities such as length, diameter, surface texture, conductivity, and elasticity. There is room for further study involving optimization of parameters such as temperature, monomer concentration, and flow velocity of the monomer solution.by Angela Y. Chen.S.B

Decreased Interleukin-4 Release from the Neurons of the Locus Coeruleus in Response to Immobilization Stress

It has been demonstrated that immobilization (IMO) stress affects neuroimmune systems followed by alterations of physiology and behavior. Interleukin-4 (IL-4), an anti-inflammatory cytokine, is known to regulate inflammation caused by immune challenge but the effect of IMO on modulation of IL-4 expression in the brain has not been assessed yet. Here, it was demonstrated that IL-4 was produced by noradrenergic neurons in the locus coeruleus (LC) of the brain and release of IL-4 was reduced in response to IMO. It was observed that IMO groups were more anxious than nontreated groups. Acute IMO (2 h/day, once) stimulated secretion of plasma corticosterone and tyrosine hydroxylase (TH) in the LC whereas these increments were diminished in exposure to chronic stress (2 h/day, 21 consecutive days). Glucocorticoid receptor (GR), TH, and IL-4-expressing cells were localized in identical neurons of the LC, indicating that hypothalamic-pituitary-adrenal- (HPA-) axis and sympathetic-adrenal-medullary- (SAM-) axis might be involved in IL-4 secretion in the stress response. Accordingly, it was concluded that stress-induced decline of IL-4 concentration from LC neurons may be related to anxiety-like behavior and an inverse relationship exists between IL-4 secretion and HPA/SAM-axes activation

Large displacement fast conducting polymer actuators

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (leaves 93-96).Conducting polymers are a promising class of electroactive materials that undergo volumetric changes under applied potentials, which make them particularly useful for many actuation applications. Polypyrrole , is one of the most common conducting polymers of choice for the development of actuator technologies and has been well characterized in its mechanical, electrical, and electrochemical response. Although capable of producing almost 10 times more active stress for a given cross-sectional area than skeletal muscle, strains are relatively low on the order of 1 to 2 %, as are strain rates, which are on the order of a couple percent per second. Small strains can be amplified to produce large bending displacements by configuring the conducting polymer film in a trilayer configuration with two conducting polymer films sandwiching an electrolyte gel layer. This thesis focuses on the development of conducting polymer bending actuators in air. There is a strong correlation found between applied voltage, temperature, and the speed of actuation. Several experiments were carried out to determine the effect of temperature on the mechanical, electrical, and electrochemical properties of the components of the trilayer.(cont.) This data coupled with thermal profiles of trilayers during actuation, electrochemical profiles, and force generation plots of the trilayers shed light on how these bending actuators can be optimized and integrated into different applications such as propulsion mechanisms for autonomous underwater vehicles.by Angela Ying Ju Chen.S.M

Quantum dot-induced cell death involves Fas upregulation and lipid peroxidation in human neuroblastoma cells

BACKGROUND: Neuroblastoma, a frequently occurring solid tumour in children, remains a therapeutic challenge as existing imaging tools are inadequate for proper and accurate diagnosis, resulting in treatment failures. Nanoparticles have recently been introduced to the field of cancer research and promise remarkable improvements in diagnostics, targeting and drug delivery. Among these nanoparticles, quantum dots (QDs) are highly appealing due to their manipulatable surfaces, yielding multifunctional QDs applicable in different biological models. The biocompatibility of these QDs, however, remains questionable. RESULTS: We show here that QD surface modifications with N-acetylcysteine (NAC) alter QD physical and biological properties. In human neuroblastoma (SH-SY5Y) cells, NAC modified QDs were internalized to a lesser extent and were less cytotoxic than unmodified QDs. Cytotoxicity was correlated with Fas upregulation on the surface of treated cells. Alongside the increased expression of Fas, QD treated cells had increased membrane lipid peroxidation, as measured by the fluorescent BODIPY-C(11 )dye. Moreover, peroxidized lipids were detected at the mitochondrial level, contributing to the impairment of mitochondrial functions as shown by the MTT reduction assay and imaged with confocal microscopy using the fluorescent JC-1 dye. CONCLUSION: QD core and surface compositions, as well as QD stability, all influence nanoparticle internalization and the consequent cytotoxicity. Cadmium telluride QD-induced toxicity involves the upregulation of the Fas receptor and lipid peroxidation, leading to impaired neuroblastoma cell functions. Further improvements of nanoparticles and our understanding of the underlying mechanisms of QD-toxicity are critical for the development of new nanotherapeutics or diagnostics in nano-oncology

Akt1-Inhibitor of DNA binding2 is essential for growth cone formation and axon growth and promotes central nervous system axon regeneration.

Mechanistic studies of axon growth during development are beneficial to the search for neuron-intrinsic regulators of axon regeneration. Here, we discovered that, in the developing neuron from rat, Akt signaling regulates axon growth and growth cone formation through phosphorylation of serine 14 (S14) on Inhibitor of DNA binding 2 (Id2). This enhances Id2 protein stability by means of escape from proteasomal degradation, and steers its localization to the growth cone, where Id2 interacts with radixin that is critical for growth cone formation. Knockdown of Id2, or abrogation of Id2 phosphorylation at S14, greatly impairs axon growth and the architecture of growth cone. Intriguingly, reinstatement of Akt/Id2 signaling after injury in mouse hippocampal slices redeemed growth promoting ability, leading to obvious axon regeneration. Our results suggest that Akt/Id2 signaling is a key module for growth cone formation and axon growth, and its augmentation plays a potential role in CNS axonal regeneration

Exploring the potential of technology to promote exercise snacking for older adults who are prefrail in the home setting: user-centered design study.

Older adults have an increased risk of falls, injury, and hospitalization. Maintaining/increasing participation in physical activity (PA) into older age can prevent some of the age-related declines in physical functioning that may contribute to loss of independence and lower reported quality of life. 'Exercise snacking' has been created to overcome some commonly cited barriers to exercise and encourage older adults to engage in muscle strength and balance activity, but the best way to deliver and support this novel format remains unknown. Our aim was to explore: a) how the novel 'exercise snacking' approach, i.e. incorporating short bouts of strength and balance activities into everyday routines, could be supported by technology within a home setting; and b) what types of technologies would be acceptable for pre-frail older adults. Two design workshops (Study 1) were conducted, to understand older adults' (n=11, aged 69-89 years old) attitudes towards technology aimed at supporting exercise snacking at home and to inform the design of interactive prototypes. Based on the findings of Study 1, a feasibility home evaluation (Study 2) was conducted over one day for two prototypes (n=5 participants, aged 69-80). Participants were interviewed over the telephone afterwards about their experience. Transcripts were analyzed using Framework analysis. Results showed participants were positive towards using technology at home to support exercise snacking, but both the exercises and technology would need to be simple and match participants' everyday routines. Workshop discussions (Study 1) led to the design of two prototypes using a pressure mat to support resistance and balance exercises. The home evaluation (Study 2) identified that participants reported potential in using smart devices to support exercise snacking, but the low fidelity of the prototypes influenced participants' attitudes towards them. It also hampered the acceptability of these initial versions and highlighted challenges in fitting exercise snacking into everyday life. The study concluded that older adults were positive about using technology in their homes to support strength and balance exercise snacking. We have identified key points around the suitability of the home environment for facilitating exercise snacking. While promising, the initial prototypes' further refinement and optimization prior to feasibility, acceptability and efficacy testing is required. Developers and researchers can use these findings to inform the development and evaluation of more sophisticated technologies for integration in the home environment to support PA