Study of limitations and attributes of microprocessor testing techniques

All microprocessor units have a similar architecture from which a basic test philosophy can be adopted and used to develop an approach to test each module separately in order to verify the functionality of each module within the device using the input/output pins of the device and its instruction set; test for destructive interaction between functional modules; and verify all timing, status information, and interrupt operations of the device. Block and test flow diagrams are given for the 8080, 8008, 2901, 6800, and 1802 microprocessors. Manufacturers are listed and problems encountered in testing the modules are discussed. Test equipment and methods are described

Challenges In Discharge Planning for Adults Transitioning From an Inpatient Psychiatric Level of Care Experiencing Homelessness

Mental illness and the homeless population are a growing concern in the United States. Homeless individuals utilize emergency rooms and acute inpatient stays more than those with housing. Social workers play a vital role in discharge planning, starting on the first day of admission. This action research study explored the challenges of social workers developing discharge plans for adults transitioning from an inpatient psychiatric level of care experiencing homeless. The theoretical framework implemented in this study was systems theory. Data were collected from 12 purposively selected master’s level social workers in the format of individual and focus group interviews. Eight social workers participated in individual interviews and three in the focus group. Data gathered from the individual and focus group interviews yielded four participant-driven themes that answered the research question. The themes were lack of resources, lack of collaboration, length of stay, and client-related factors. The findings from this study identified key challenges of social workers’ discharge planning for adults transitioning from an inpatient level of care experiencing homelessness, limited resources for this population, lack of collaboration among stakeholders, time limits to develop safe discharge plans, and patient factors such as limited supports. Addressing the identified challenges in this study could promote positive social change on local and national levels by improving the discharge planning process in hospital settings for adult patients experiencing homelessness. The results of this study could assist in reducing the number of individuals being discharged to the streets and shelters from hospital settings

Conserving Waterlogged Rope: A Review of Traditional Methods and Experimental Research with Polyethylene Glycol

The excavation of Sieur de la Salle's ship, La Belle, yielded a large amount of waterlogged rope requiring conservation. A history of hemp and rope manufacture is reviewed to assist in the identification of the materials and rope-work recovered from the La Belle, as well as to assist in selecting an appropriate conservation treatment. A summary of several methods used to conserve cordage is presented. Time has shown that not all of these treatment methods have remained viable options, and that continued study and experimentation are needed so that the conservator has the tools to develop an appropriate conservation plan for each artifact. The majority of La Belle's cordage was conserved using the passivation polymers method developed by Dr. C. Wayne Smith and Dr. Donny L. Hamilton, both of Texas A&M University, in conjunction with Dow Corning Corporation, Midland, Michigan. An experiment applying knowledge gleaned from the passivation polymers process to polyethylene glycol (PEG) impregnation was conducted in an attempt to stabilize the PEG within the rope. The results were good; the rope retained some flexibility and appears stable with a slightly darker color than with silicone oil

Challenges In Discharge Planning for Adults Transitioning From an Inpatient Psychiatric Level of Care Experiencing Homelessness

Mental illness and the homeless population are a growing concern in the United States. Homeless individuals utilize emergency rooms and acute inpatient stays more than those with housing. Social workers play a vital role in discharge planning, starting on the first day of admission. This action research study explored the challenges of social workers developing discharge plans for adults transitioning from an inpatient psychiatric level of care experiencing homeless. The theoretical framework implemented in this study was systems theory. Data were collected from 12 purposively selected master’s level social workers in the format of individual and focus group interviews. Eight social workers participated in individual interviews and three in the focus group. Data gathered from the individual and focus group interviews yielded four participant-driven themes that answered the research question. The themes were lack of resources, lack of collaboration, length of stay, and client-related factors. The findings from this study identified key challenges of social workers’ discharge planning for adults transitioning from an inpatient level of care experiencing homelessness, limited resources for this population, lack of collaboration among stakeholders, time limits to develop safe discharge plans, and patient factors such as limited supports. Addressing the identified challenges in this study could promote positive social change on local and national levels by improving the discharge planning process in hospital settings for adult patients experiencing homelessness. The results of this study could assist in reducing the number of individuals being discharged to the streets and shelters from hospital settings

RNA interference can be used to disrupt gene function in tardigrades

How morphological diversity arises is a key question in evolutionary developmental biology. As a long-term approach to address this question, we are developing the water bear Hypsibius dujardini (Phylum Tardigrada) as a model system. We expect that using a close relative of two well-studied models, Drosophila (Phylum Arthropoda) and Caenorhabditis elegans (Phylum Nematoda), will facilitate identifying genetic pathways relevant to understanding the evolution of development. Tardigrades are also valuable research subjects for investigating how organisms and biological materials can survive extreme conditions. Methods to disrupt gene activity are essential to each of these efforts, but no such method yet exists for the Phylum Tardigrada. We developed a protocol to disrupt tardigrade gene functions by double-stranded RNA-mediated RNA interference (RNAi). We show that targeting tardigrade homologs of essential developmental genes by RNAi produced embryonic lethality, whereas targeting green fluorescent protein did not. Disruption of gene functions appears to be relatively specific by two criteria: targeting distinct genes resulted in distinct phenotypes that were consistent with predicted gene functions, and by RT-PCR, RNAi reduced the level of a target mRNA and not a control mRNA. These studies represent the first evidence that gene functions can be disrupted by RNAi in the phylum Tardigrada. Our results form a platform for dissecting tardigrade gene functions for understanding the evolution of developmental mechanisms and survival in extreme environments

Translocation of structured polynucleotides through nanopores

We investigate theoretically the translocation of structured RNA/DNA molecules through narrow pores which allow single but not double strands to pass. The unzipping of basepaired regions within the molecules presents significant kinetic barriers for the translocation process. We show that this circumstance may be exploited to determine the full basepairing pattern of polynucleotides, including RNA pseudoknots. The crucial requirement is that the translocation dynamics (i.e., the length of the translocated molecular segment) needs to be recorded as a function of time with a spatial resolution of a few nucleotides. This could be achieved, for instance, by applying a mechanical driving force for translocation and recording force-extension curves (FEC's) with a device such as an atomic force microscope or optical tweezers. Our analysis suggests that with this added spatial resolution, nanopores could be transformed into a powerful experimental tool to study the folding of nucleic acids.Comment: 9 pages, 5 figure

Distribution of graph-distances in Boltzmann ensembles of RNA secondary structures

Large RNA molecules often carry multiple functional domains whose spatial arrangement is an important determinant of their function. Pre-mRNA splicing, furthermore, relies on the spatial proximity of the splice junctions that can be separated by very long introns. Similar effects appear in the processing of RNA virus genomes. Albeit a crude measure, the distribution of spatial distances in thermodynamic equilibrium therefore provides useful information on the overall shape of the molecule can provide insights into the interplay of its functional domains. Spatial distance can be approximated by the graph-distance in RNA secondary structure. We show here that the equilibrium distribution of graph-distances between arbitrary nucleotides can be computed in polynomial time by means of dynamic programming. A naive implementation would yield recursions with a very high time complexity of O(n^11). Although we were able to reduce this to O(n^6) for many practical applications a further reduction seems difficult. We conclude, therefore, that sampling approaches, which are much easier to implement, are also theoretically favorable for most real-life applications, in particular since these primarily concern long-range interactions in very large RNA molecules.Comment: Peer-reviewed and presented as part of the 13th Workshop on Algorithms in Bioinformatics (WABI2013

Statistical mechanics of RNA folding: importance of alphabet size

We construct a minimalist model of RNA secondary-structure formation and use it to study the mapping from sequence to structure. There are strong, qualitative differences between two-letter and four or six-letter alphabets. With only two kinds of bases, there are many alternate folding configurations, yielding thermodynamically stable ground-states only for a small set of structures of high designability, i.e., total number of associated sequences. In contrast, sequences made from four bases, as found in nature, or six bases have far fewer competing folding configurations, resulting in a much greater average stability of the ground state.Comment: 7 figures; uses revtex

Helicon Plasma Injector and Ion Cyclotron Acceleration Development in the VASIMR Experiment

In the Variable Specific Impulse Magnetoplasma Rocket (VASIMR) radio frequency (rf) waves both produce the plasma and then accelerate the ions. The plasma production is done by action of helicon waves. These waves are circular polarized waves in the direction of the electron gyromotion. The ion acceleration is performed by ion cyclotron resonant frequency (ICRF) acceleration. The Advanced Space Propulsion Laboratory (ASPL) is actively developing efficient helicon plasma production and ICRF acceleration. The VASIMR experimental device at the ASPL is called VX-10. It is configured to demonstrate the plasma production and acceleration at the 10kW level to support a space flight demonstration design. The VX-10 consists of three electromagnets integrated into a vacuum chamber that produce magnetic fields up to 0.5 Tesla. Magnetic field shaping is achieved by independent magnet current control and placement of the magnets. We have generated both helium and hydrogen high density (>10(exp 18) cu m) discharges with the helicon source. ICRF experiments are underway. This paper describes the VX-10 device, presents recent results and discusses future plans