Topologies for ad-hoc networks utilizing directional antennas with restricted fields of view

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, February 2006.Includes bibliographical references (p. 63-64).ORCLE (Optical/RF Combined Link Experiment), is an airborne network in which aircraft have multiple directional antennas that are restricted in their pointing direction. A pair of aircraft in ORCLE can be linked if they both have an antenna pointing at each other. Four topology algorithms, which coordinate the pointing of the antennas and attempt to maximize a connectedness metric, are presented and analyzed using a custom 2D simulation platform. Three of the algorithms are based on the Relative Neighbor Graph (RNG): the first constrains the RNG to requirements of the ORCLE network, the second augments the constrained RNG with edges from the Delaunay Triangulation, and the third algorithm tries to improve on the second by adding edges to reduce the diameter. The final algorithm uses a novel concept of overlapping sets of nested convex hulls to select the links of the network. All algorithms are stateless and interface with a Target Transition Layer, which gradually migrates topologies to prevent a large number of edges from being lost simultaneously. Scenes with varying node density, number of terminals per node, fields of view, and re-targeting delays are used to test the algorithms against a wide range of possible situations.by Brian C. Anderson.M.Eng

Development of novel polymeric materials for gene therapy and pH-sensitive drug delivery: modeling, synthesis, characterization, and analysis

The aim of this work was to obtain a fundamental understanding of drug release mechanisms from polymers that undergo thermoreversible gelation and to synthesize new polymers based on these that exhibit both pH and temperature sensitivity. Novel block and random copolymers with cationic character have been developed for drug delivery and gene therapy applications. The development of these materials began with a study of the mechanism of drug release from poly(ethylene oxide) (PEO) and poly(propylene oxide) (PPO) block copolymers. This study revealed the release rates of drugs from water-soluble hydrogels composed of the PEO-PPO-PEO block copolymer PluronicRTM F127 was dictated almost solely by the rate of interfacial dissolution at the water/gel interface. A setup was designed to measure drug release from such soluble systems in order to avoid confounding hydrodynamic effects as a result of shear on the delicate polymer/gel interface. This study was followed by a complementary analysis of the effect ionic salts play in the phase transitions and drug release profiles in aqueous F127 solutions.;In an attempt to incorporate pH sensitivity into such drug release systems, several block copolymers of poly(N,N-diethylaminoethyl methacrylate) (PDEAEM), PEO and PPO were synthesized via anionic polymerization. Diblock materials (PEO-b-PDEAEM), either with or without a carboxylic acid endcap, were synthesized and characterized. Tablet dissolution experiments demonstrated pH-sensitivity in their drug release profiles relative to PEO tablets. Pentablock materials (PDEAEM-b-PEO-b-PPO- b-PEO-b-PDEAEM) were synthesized that maintain the thermoreversible gelation and micellization properties of F127 while introducing pH-dependent release from aqueous gels of the copolymer. This is the first example of non-crosslinked materials that exhibit both pH- and temperature-sensitive behavior. Using a similar synthesis route, random copolymers of PDEAEM and poly(poly(ethylene glycol) methyl ether methacrylate)) (PEGME) were synthesized which are water soluble and non-cytotoxic, whereas homopolymers of PDEAEM are neither. These materials have potential as gene therapy vectors

Master of Science

thesisIn this study, our objectives were to 1) Examine performance on an objective measure of reward-related cognitive impulsivity (delay discounting) among self-reported habitual short sleepers not reporting daytime dysfunction in comparison to those reporting dysfunction and conventional sleepers; 2) Inform the debate regarding what type and duration of short sleep meaningfully influences cognitive impulsivity; 3) Compare the predictive utility of sleep duration and perceived daytime dysfunction to other factors previously shown to influence cognitive impulsivity via delay discounting performance (age, income, education, and fluid intelligence). We analyzed data from 1,190 adults from the Human Connectome Project database. Participants were grouped on whether they reported habitual short (≤ 6 hours) vs. conventional (7 to 9 hours) sleep duration and whether they perceived daytime dysfunction using the Pittsburgh Sleep Quality Index. Results indicated that short sleepers not reporting dysfunction evidenced increased delay discounting compared to conventional sleepers, but were not significantly different from short sleepers reporting dysfunction. Regardless of perceived dysfunction, all short sleepers exhibited increased delay discounting compared to all conventional sleepers. Of the variables examined, self-reported sleep duration was the strongest predictor of delay discounting behavior between groups and across all 1,190 participants. We conclude that individuals who report habitual short sleep are likely to exhibit increased reward-related cognitive impulsivity regardless of whether they perceive sleep-related daytime impairment. Therefore, there is reason to suspect that these individuals exhibit more daytime dysfunction, in the form of reward-related cognitive impulsivity, than they may assume. Current findings suggest that assessment of sleep duration over the prior month has meaningful predictive utility for human reward-related impulsivity

Why was I Rejected? How the Attributed Reason for Social Rejection Impacts Subsequent Behavior.

It is proposed that differences in rejection attribution could yield variations in subsequent prosocial behavior. To test the attribution hypothesis, 109 participants were randomly assigned to a performance based rejection, a personally based rejection, or a control condition and then worked with an ostensible partner via the Internet to develop uses for a common household item. Prosocial behavior was measured by the number of uses a participant generated (working harder for the team). When generating creative uses, participants in the rejection conditions performed significantly worse than nonrejected participants (F(2,74) = 4.576, p\u3c.05, r2=.11). However, in contradiction to the attribution hypothesis, participants in the 2 rejection conditions did not differ in performance. Explanations for why the rejection attribution hypothesis was not supported are discussed in addition to directions for future research regarding rejection attribution

FY 2000 Juvenile Justice and Delinquency Prevention Act Compliance Monitoring Report

The Juvenile Justice and Delinquency Prevention Act (JJDPA) mandates removal of status offenders and nonoffenders from secure detention and correctional facilities, sight and sound separation of juveniles and adults, and removal of juveniles from adult jails and lockups. In Alaska, 2 instances of status offenders held in secure detention were recorded in FY 2000, compared with 485 violations in the baseline year of CY 1976. In Alaska, 17 separation violations were recorded in FY 2000 (45 projected), representing a 98% reduction from the CY 1976 baseline of 824 violations. 82 jail removal violations were projected (50 actual), representing an substantial reduction from the CY 1980 baseline.Alaska Department of Health and Social Services, Division of Juvenile JusticeA. General Information / B. Removal of Status Offenders and Nonoffenders from Secure Detention and Correctional Facilities / C. De Minimis Request / D. Progress Made in Achieving Removal of Status Offenders and Nonoffenders from Secure Detention and Correctional Facilities / E. Separation of Juveniles and Adults / F. Removal of Juveniles from Adult Jails and Lockups / G. De Minimis Request: Substantive / APPENDICES / I. Method of Analysis / II. Fiscal Year 2000 Violations by Offense Type and Location / III. Common Offense Acronym

An in vitro evaluation of the efficacy of tedizolid: implications for the treatment of skin and soft tissue infections

Skin and soft tissue infections (SSTI) are among the most commonly occurring infections and evidence suggests that these are increasing world-wide. The aetiology is diverse, but Staphylococcus aureus predominate and these are often resistant to antimicrobials that were previously effective. Tedizolid is a new oxazolidinone-class antibacterial indicated for the treatment of adults with SSTI caused by Gram-positive pathogens, including S. aureus. The aim of this study was to evaluate the in vitro efficacy of tedizolid in comparison to other clinically used antibacterials against antibiotic sensitive- and resistant-staphylococci, grown in planktonic cultures and as biofilms reflecting the growth of the microorganism during episodes of SSTI. Against a panel of 66 clinical staphylococci, sensitivity testing revealed that a lower concentration of tedizolid was required to inhibit the growth of staphylococci compared to linezolid, vancomycin and daptomycin; with the tedizolid MIC being 8-fold (S. aureus) or 4-fold (S. epidermidis) below that obtained for linezolid. In addition, cfr+ linezolid-resistant strains remained fully susceptible to tedizolid. Against S. aureus biofilms, 10×MIC tedizolid was superior or comparable with 10×MIC comparator agents in activity, and superior to 10×MIC linezolid against those formed by S. epidermidis (65 vs. 33% reduction, respectively). Under flow-conditions both oxazolidinones at 10×MIC statistically out-performed vancomycin in their ability to reduce the viable cell count within a S. aureus biofilm with fewer the 12% of cells surviving compared to 63% of cells. In conclusion, tedizolid offers a realistic lower-dose alternative agent to treat staphylococcal SSTI, including infections caused by multi-drug resistant strains

Water quality and recreational angling demand in Ireland. ESRI Research Bulletin 2016/2/3

About 8% of the adult population in Ireland consider themselves to be recreational anglers. Including tourist anglers from Northern Ireland, Great Britain and elsewhere, approximately 400,000 people per annum fish in Ireland’s rivers, lakes and coastal waters. The economic contribution of recreational anglers to the local economy, in terms of expenditure on equipment and services plus food and accommodation exceeds €800 million per annum and supports 11,000 jobs, primarily in rural and peripheral communities