Home work in the elementary school: a study in two communities

Thesis (Ed.M.)--Boston Universit

Comments on “Electric current and electric field induced in a human body when exposed to an incident electric field near the resonant frequency”

[For original paper see R. W. P. King, IEEE Trans. Microwave Theory Tech., vol. 48, no. 9, pp. 147-53 (2000).] The author makes two observations on the original article. The commentator questions whether a seated person is well modeled as a right circular cylinder. The second observation is that King cites only microwave studies on mice to show that electromagnetic radiation causes malignancies. These studies themselves are widely disputed. He then uses simple dimensional scaling to show that 2.45 GHz for a mouse scales to 100 MHz for a man. Such a scaling law may be useful in calculating the resonant frequency for a human subject versus a mouse when treated as antennas, but such scaling is meaningless when the physics of a hypothetical carcinogenic process are unknown

Nanoelectronics manufacture, inspection, and repair using thermal dip pen nanolithography

Issued as final reportUnited States. Office of Naval Researc

Valence band offset of InN/AlN heterojunctions measured by X-ray photoelectron spectroscopy

The valence band offset of wurtzite-InN/AlN (0001) heterojunctions is determined by x-ray photoelectron spectroscopy to be 1.52±0.17 eV. Together with the resulting conduction band offset of 4.0±0.2 eV, a type-I heterojunction forms between InN and AlN in the straddling arrangement

Tip-Based Nanofabrication of Arbitrary Shapes of Graphene Nanoribbons for Device Applications

Graphene nanoribbons (GNRs) have promising applications in future nanoelectronics, chemical sensing and electrical interconnects. Although there are quite a few GNR nanofabrication methods reported, a rapid and low-cost fabrication method that is capable of fabricating arbitrary shapes of GNRs with good-quality is still in demand for using GNRs for device applications. In this paper, we present a tip-based nanofabrication method capable of fabricating arbitrary shapes of GNRs. A heated atomic force microscope (AFM) tip deposits polymer nanowires atop a CVD-grown graphene surface. The polymer nanowires serve as an etch mask to define GNRs through one step of oxygen plasma etching similar to photoresist in conventional photolithography. Various shapes of GNRs with either linear or curvilinear features are demonstrated. The width of the GNR is around 270 nm and is determined by the width of depositing polymer nanowire, which we estimate can be scaled down 15 nms. We characterize our TBN-fabricated GNRs using Raman spectroscopy and I-V measurements. The measured sheet resistances of our GNRs fall within the range of 1.65 kΩ - 2.64 kΩ-1 in agreement with previously reported values. Furthermore, we determined the high-field breakdown current density of GNRs to be approximately 2.94x108 A/cm2. This TBN process is seamlessly compatible with existing nanofabrication processes, and is particularly suitable for fabricating GNR based electronic devices including next generation DNA sequencing technologies and beyond silicon field effect transistors

Evolution of an ancient protein function involved in organized multicellularity in animals.

To form and maintain organized tissues, multicellular organisms orient their mitotic spindles relative to neighboring cells. A molecular complex scaffolded by the GK protein-interaction domain (GKPID) mediates spindle orientation in diverse animal taxa by linking microtubule motor proteins to a marker protein on the cell cortex localized by external cues. Here we illuminate how this complex evolved and commandeered control of spindle orientation from a more ancient mechanism. The complex was assembled through a series of molecular exploitation events, one of which - the evolution of GKPID's capacity to bind the cortical marker protein - can be recapitulated by reintroducing a single historical substitution into the reconstructed ancestral GKPID. This change revealed and repurposed an ancient molecular surface that previously had a radically different function. We show how the physical simplicity of this binding interface enabled the evolution of a new protein function now essential to the biological complexity of many animals

Corporate Political Power and US Foreign Policy, 1981-2002: The Role of the Policy-Planning Network

Recent empirical work has offered strong support for ‘biased pluralism’ and ‘economic elite’ accounts of political power in the United States, according a central role to interest groups as a mechanism through which corporate influence is exerted. Here, we propose an additional channel of influence for corporate interests: the ‘policy-planning network,’ consisting of corporate- dominated foundations, think tanks, and elite policy-discussion groups. To evaluate this assertion, we coded the policy preferences of one key policy-discussion group, the Council on Foreign Relations (CFR), on 295 foreign policy issues during the 1981-2002 period. In logistic regression analyses, the preferences of economic elites and the CFR were positive, statistically significant predictors of foreign policy outcomes while interest group preferences were not. These findings were further supported with a qualitative investigation of the patterns of CFR ‘successes’ and ‘failures.’ We conclude that ‘biased pluralism’ models should include corporate influence exerted through the policy-planning network