J. John Harris

Suspensions and Expulsions of Male and Black Students A Study of the Causes of Disproportionality

Black students are suspended far more often than white students. The extent of disproportion depends largely upon school and staff characteristics.

Amplifications of EGFR gene and protein expression of EGFR, Her-2/neu, c-kit, and androgen receptor in phyllodes tumor of the prostate.

Phyllodes tumor of the prostate is a rare neoplasm with an unpredictable clinical behavior. It may undergo early recurrence with sarcomatous transformation or may even metastasize. Because targeted therapies have shown great success against several malignancies, there is hope that these same therapies may show similar promise in the treatment of other neoplasms. This study was undertaken to investigate both amplification of the epidermal growth factor receptor (EGFR) gene by fluorescence in situ hybridization and the overexpression of EGFR, Her-2/neu, CD117 (c-kit), and androgen receptor by immunohistochemical staining in a series of 11 phyllodes tumors of the prostate. In the stromal elements, EGFR gene amplification was present in four of 11 tumors and polysomy chromosome 7 was present in two of 11 tumors. No amplification was present in the epithelial components. Only one of 11 tumors had polysomy of chromosome 7 in the epithelial components. Immunohistochemically, in the stromal components, EGFR expression was demonstrable in four of 11 tumors and androgen receptor was demonstrated in six of 10 tumors. Neither Her-2/neu nor c-kit expression was seen in the stromal components of any of the 11 tumors. In the epithelial components, EGFR expression was present in all 11 tumors with strong staining in the basal cell layers and weak or no staining in luminal epithelium; androgen receptor expression was seen in seven of 10 tumors; Her-2/neu was weakly positive in four of 11 tumors; and c-kit expression was present focally and weakly in two of 11 cases with only 2–5% of cells staining. The highest staining intensity and the highest percentage of positively staining cells were seen with EGFR immunostaining in both the stromal and epithelial (mainly basal cells) components. Androgen receptor staining showed the next highest staining intensity and percentage of positive cells in both components. Her-2/neu and c-kit were only weakly or infrequently expressed in the epithelial components of prostatic phyllodes tumors. Our data indicate that EGFR and androgen receptor are frequently and strongly expressed in both epithelial and stromal components of prostatic phyllodes tumors. EGFR gene amplification is frequently present in prostatic phyllodes tumors and may account for one of the mechanisms leading to protein overexpression in some but not all cases. Anti-EGFR and/or antiandrogen agents may be potentially useful for management of patients with tumors expressing EGFR and/or androgen receptor.

Adaptive Scheduling Algorithms for the Dynamic Distribution and Parallel Execution of Spatial Agent-Based Models

In previous work [7], we proposed a general framework for defining agent-based models (ABMs) and introduced two algorithms for the automatic parallelization of agent-based models: a general version P-ABM G for all ABMs definable in the framework and a more specific variant P-ABM S for “spatial ABMs”, which can utilize the additional spatial information to obtain performance improvements. Both algorithms can automatically distribute ABMs over multiple processors and dynamically adjust the degree of parallelization based on available computational resources throughout the simulation runs. However, they are not sensitive to inefficiencies in the sequence in which agents in each parallel simulation instance are updated.

Building a trusted image for embedded systems

In this work, we propose PlugNPlay Trust, an integrity measurement framework which enables a remote system to evaluate the integrity and state of an embedded node. The PlugNPlay Trust design exploits the relatively static nature of embedded communication systems and uses a Trusted Platform Module (TPM) to measure the state and provide identity verification for the embedded host. This framework enables remote parties to confirm the integrity of embedded communication systems, thereby limiting the effects and the proliferation of malware in compromised system. We implement a prototype of the PlugNPlay framework using Live CD technologies and a USB Flash-drive. We measure the performance of our system and show that our design choices result in efficient measurement and verification of system integrity.

StaticTrust: A Practical Framework for Trusted Networked Devices

Given the proliferation of malware and malicious activities, the integrity of communication systems is an ever growing concern. In this work, we propose StaticTrust, an integrity measurement framework which enables a system to evaluate the integrity and state of a remote client prior to providing trusted communication services. StaticTrust is designed for a specific class of network devices that have software images that change infrequently and require tight configuration control (e.g. routers, switches, trusted gateways, or high-low guards). StaticTrust exploits the relatively static nature of these communication systems and uses a Trusted Platform Module (TPM) to measure the state and provide identity verification for the device. This framework, coupled with the attestation and dynamic firewall exception services we authored, enables remote parties to confirm the integrity of clients, thereby limiting the effects and the proliferation of malware in a compromised system. We implement a prototype of the StaticTrust framework and measure the performance of our system to show that our design choices for constructing the software image result in efficient measurement and verification of system integrity.