Sonogashira/N-acyliminium ion aromatic π-cyclisation processes: access to tetra- and pentacyclic lactams

Application of the Sonogashira reaction of N-alkynylimides with 2-iodophenol or 2-iodo-N-tosylaniline affords 2-(N-alkylimino)-benzofurans and indoles in good yield. Selective partial reduction of the latter followed by treatment with TsOH generates N-acyliminium ions, which cyclise to afford tetra- and pentacyclic lactams in good yield. The latter are reduced to the analogous cyclic amines by BH3

NASA space materials research

The effect of the space environment on: (1) thermal control coatings and thin polymer films; (2) radiation stability of 250 F and 350 F cured graphite/epoxy composites; and (3) the thermal mechanical stability of graphite/epoxy, graphite/glass composites are considered. Degradation in mechanical properties due to combined radiation and thermal cycling is highlighted. Damage mechanisms are presented and chemistry modifications to improve stability are suggested. The dimensional instabilities in graphite/epoxy composites associated with microcracking during thermal cycling is examined as well as the thermal strain hysteresis found in metal-matrix composites

Qualitative Evaluation of the Java Intelligent Tutoring System

In an effort to support the growing trend of the Java programming language and to promote web-based personalized education, the Java Intelligent Tutoring System (JITS) was designed and developed. This tutoring system is unique in a number of ways. Most Intelligent Tutoring Systems require the teacher to author problems with corresponding solutions. JITS, on the other hand, requires the teacher to only supply the problem and problem specification. JITS is designed to “intelligently” examine the student’s submitted code and determines appropriate feedback based on a number of factors such as JITS’ cognitive model of the student, the student’s skill level, and problem details. JITS is intended to be used by beginner programming students in their first year of College or University. This paper discusses the important aspects of the design and development of JITS, the qualitative methods and procedures, and findings. Research was conducted at the Sheridan Institute of Technology and Advanced Learning, Ontario, Canada

Developmental Process Model for the Java Intelligent Tutoring System.

The Java Intelligent Tutoring System (JITS) was designed and developed to support the growing trend of Java programming around the world. JITS is an advanced web-based personalized tutoring system that is unique in several ways. Most programming Intelligent Tutoring Systems require the teacher to author problems with corresponding solutions. JITS, on the other hand, requires the teacher to supply only the problem and problem specification. JITS rigorously analyzes the student’s submitted code, determines the intent of the student, and intelligently guides the student towards a potentially unique solution to the programming problem. JITS is intended to be used by beginner programming students in their first year of College or University. This article discusses the process by which the design and development of JITS took place. JITS has been and is currently being field-tested at the Sheridan Institute of Technology and Advanced Learning

Determining the Effectiveness of the 3D Alice Programming Environment at the Computer Science I Level

Student retention in Computer Science is becoming a serious concern among Educators in many colleges and universities. Most institutions currently face a significant drop in enrolment in Computer Science. A number of different tools and strategies have emerged to address this problem (e.g., BlueJ, Karel Robot, etc.). Although these tools help to minimize attrition, they have not made significant improvements to this widespread problem. A newcomer to the scene called Alice has been met with positive results by captivating student interest through its rich 3D visual programming environment. During the fall of 2005, Alice, a newly published textbook, and numerous resources were used in Computer Science I at McMaster University. This paper provides an overview of Alice, an assessment of this new course including qualitative surveys, informal observations, and quantitative analysis including student performance score results. Despite numerous technical problems, it was found that the Alice Group exceeded the performance of Comparison Groups: F(1,93) = 30.322, p \u3c .001 (between C1 and Alice group); F(1,81) = 4.182, p = .044 (between C2 and Alice Group)

Indium phosphide - langmuir film mis devices

Langramuir blodgett films are an interesting example of two dimensional order structure. Their fabrication involves the building-up of a multilayer firmly repeated deposition of single monomolecular layers upon the substrate material. The resultant structure is of defined thickness and excellent uniformity. Because of these qualities, Langmuir films enjoy potential applicatons in many areas of modern science. In particular , their excellent insulating properties have led to the proposition of their use within the semiconductor device industry. Indium phosphide, although a relatively new semiconductor, is already becoming an important device material, particularly in areas where its high mobility gives rapid device response and good high frequency operation. This thesis combines these two materials, and looks at the electrical behaviour of InP/Langmuir film metal-insulator-semiconductor (MIF devices and their associated structures. The Langrauir-Blodgett process is a low temperature deposition technique, and thus induces little or no surface damage to its recipient substrate. Because of this, it is likely that the chemical surface of the InP, prior to deposition, will be of critical importance in defining the device characteristics. This has in fact been found to b'. the case, and a detailed study of the correlation between ESCA surface chemical information and vice electrical data has been undertaken. In addition, the device results obtained have been found be rather different to those produced by the use of a conventional high temperature deposition process. In order to capitalise upon the use of these organic insulating films, and the sensitive nature of the InP surface, the effect of various gases upon these device structures have been investigated. The study has revealed the existence of many interesting bulk and interface effects, and is likely to form the basis of a more detailed programme aiming to develop a range of solid state sensors

Reasoning about ideal interruptible moments: A soft computing implementation of an interruption classifier in free-form task environments

Current trends in society and technology make the concept of interruption a central human computer interaction problem. In this work, a novel soft computing implementation for an Interruption Classifier was designed, developed and evaluated that draws from a user model and real-time observations of the user\u27s actions as s/he works on computer-based tasks to determine ideal times to interact with the user. This research is timely as the number of interruptions people experience daily has grown considerably over the last decade. Thus, systems are needed to manage interruptions by reasoning about ideal timings of interactions. This research shows: (1) the classifier incorporates a user model in its’ reasoning process. Most of the research in this area has focused on task-based contextual information when designing systems that reason about interruptions; (2) the classifier performed at 96% accuracy in experimental test scenarios and significantly out-performed other comparable systems; (3) the classifier is implemented using an advanced machine learning technology—an Adaptive Neural-Fuzzy Inference System—this is unique since all other systems use Bayesian Networks or other machine learning tools; (4) the classifier does not require any direct user involvement—in other systems, users must provide interruption annotations while reviewing video sessions so the system can learn; and (5) a promising direction for reasoning about interruptions for free-form tasks–this is largely an unsolved problem

The Carboxyl-Terminal Segment of Apolipoprotein A-V Undergoes a Lipid-Induced Conformational Change

Apolipoprotein (apo) A-V is a 343-residue, multidomain protein that plays an important role in regulation of plasma triglyceride homeostasis. Primary sequence analysis revealed a unique tetraproline sequence (Pro293-Pro296) near the carboxyl terminus of the protein. A peptide corresponding to the 48-residue segment beyond the tetraproline motif was generated from a recombinant apoA-V precursor wherein Pro295 was replaced by Met. Cyanogen bromide cleavage of the precursor protein, followed by negative affinity chromatography, yielded a purified peptide. Nondenaturing polyacrylamide gel electrophoresis verified that apoA-V(296-343) solubilizes phospholipid vesicles, forming a relatively heterogeneous population of reconstituted high-density lipoprotein with Stokes’ diameters\u3e17 nm. At the same time, apoA-V(296-343) failed to bind a spherical lipoprotein substrate in vitro. Far-UV circular dichroism spectroscopy revealed the peptide is unstructured in buffer yet adopts significant R-helical secondary structure in the presence of the lipid mimetic solvent trifluoroethanol (TFE; 50% v/v). Heteronuclear multidemensional NMR spectroscopy experiments were conducted with uniformly 15N- and 15N/13C-labeled peptide in 50% TFE. Peptide backbone assignment and secondary structure prediction using TALOSþ reveal the peptide adopts R-helix secondary structure from residues 309 to 334. In TFE, apoA-V(296-343) adopts an extended amphipathic R-helix, consistent with a role in lipoprotein binding as a component of full-length apoA-V

The Economics of Allocation in Tuna Regional Fisheries Management Organizations (RFMOS)

The paper reviews existing allocation mechanisms in the five tuna regional fisheries management organizatins and shows that although they have adopted different approaches all have failed to prevent overcapacity and, or some stocks, overexploitation. As an alternative, it is proposed that each tuna regional fishing management organization establish total allowable catches by species and area, and then allocate non-transferable and permanent country shares (as a proportion of the total harvest) to member countries. Each country would be free to use or sell its annual allocation of fish that would be determined by the permanent country shares, but the sales could only be to fellow member countries. A two-tier allocation to countries of permanenet shares of a total allowable catch, and then annual harvest allocations to vessels of member countries, offers the promise of mitigating, and possibly overcoming, the twin problems of overcapacity and overexploitation in the highly migratory and high seas tuna fisheries.tuna, property rights, allocation