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Chemistry / Although molecules that bind DNA have the potential to modify gene expression, the reality of targeting DNA in a sequence-specific manner is still a problematic but worthwhile goal. The Iverson lab has been exploring DNA recognition through a motif known as threading polyintercalation based on connecting intercalating naphthalene diimide (NDI) units, which are molecules that insert themselves between DNA base pairs, together with peptide linkers. These polyintercalators interact with both DNA grooves by “threading” or winding through the DNA, like a snake might climb a ladder. Initially, two different bisintercalator modules with altered sequence specificities and different groove binding topologies were discovered and used to inspire the design of a hybrid NDI tetraintercalator. Surprisingly enough, this tetraintercalator bound sequence-specifically with a dissociation half-life of 16 days to its preferred 14 bp site, a record at the time it was reported for a synthetic DNA-binding molecule. The work reported here expands on the capabilities of this modular threading polyintercalation motif. Chapter 2 describes the ability of a new hybrid NDI tetraintercalator, where the bisintercalator modules are connected together in a different way compared to the previously studied tetraintercalator, to subtly discriminate between similar binding sites. Chapter 3 offers a structural understanding, through NMR analysis, for the sequence recognition abilities of this new tetraintercalator. Chapter 4 analyzes the binding abilities of an un-optimized NDI octaintercalator and proposes how to approach the second-generation design of longer polyintercalators. Chapter 5 describes the optimization of the originally designed NDI tetraintercalator by serially lengthening one of the linkers to produce a tetraintercalator with a 57 day dissociation half-life from its 14 bp sequence, a new record for a synthetic DNA-binding molecule. Using the optimized linker in the context of an NDI hexaintercalator allows for binding to a 22 bp designed site, a record for a synthetic non-nucleic acid molecule. Chapter 6 recounts a focused library screening to search for bisintercalators with new sequence specificities. These efforts have laid the groundwork to progress toward studies aimed at understanding how these molecules might function to prevent transcription in a sequence-dependent manner in vivo. / text

Resistance spot welding is used frequently as a successful joining method for a variety of work commonly in automotive and other manufacturing processes. Spot weld nugget is generally hidden between two sheets, causing its inspection difficult and expensive. Undersized nuggets, brittle or cracked nuggets, and excessive indentation of electrodes reveals the lack of fusion between the parts that can make the weld sub-standard. Visual inspection, pry testing and physical teardown with chisel and hammer method or a combination of them are being used traditionally. However, this study presents a more effective nondestructive inspection method based upon an ultrasonic pulse-echo technique. The theory of the technique together with the experimental verification are presented and its advantages over the other destructive and nondestructive techniques are considered.

Approved for public release; distribution is unlimited / In the past ten years reliable high-speed satellite systems have pushed slower less reliable communication systems to the bottom of the list for development programs. Concern over reduced budgets, vulnerability of expensive satellite systems, and recent advances in HF technology are creating new interest in upgrading existing HF communication systems. Nondevelopment Items (NDI) are defined as the use of off-the-shelf commercial items instead of costly, time-consuming conventional research and development programs. The Navy Department's current policies are designed to insure the maximum use of NDI to fulfill Navy requirements. The speed of HF systems can be improved using current signaling and modulation techniques, and reliability can be increased by error-correcting codes or error detection used in conjunction with automatic repeat request (ARQ) schemes. Improved HF systems not only provide survivable back-up capability, but increased capacity for present communication needs. / http://archive.org/details/longhaulcommunic00elli / Lieutenant, United States Navy

Various configurations of unidirectional carbon/epoxy composite rods were impacted radially, inspected using micro-CT scanning equipment, and tested in axial compression to measure the residual strength after impact. This data was used to correlate the relationship between impact energy, residual strength, and the peak crack area and total crack volume along the length of the specimens. These specimens represent local members of open three-dimensional composite lattice structures (e.g., based on isogrid or IsoTruss® geometries) that are continuously fabricated using advanced three-dimensional braiding techniques. The specimens were radially impacted with 2.5 J (1.9 ft-lbs), 5.0 J (3.7 ft-lbs), 7.5 J (5.6 ft-lbs), 10 J (7.4 ft-lb), 15 J (11 ft-lbs), and 20 J (15 ft-lbs) of energy, and compared to undamaged control specimens. The unidirectional core specimens were 8 mm (5/16") in diameter and were consolidated with various sleeve configurations and materials. Sleeves differed in types (bi-directional braided sleeves or unidirectional spiral wraps), nominal sleeve coverage of the core fibers (full or half), and sleeve material (Nomex Thread or Dunstone Hi-Shrink Tape). The unsupported length of the specimens used in this research was 50.8 mm (2") to ensure a strength-controlled compression failure rather than a failure due to buckling. After impact, the specimens were scanned using a micro-CT scanner at resolutions of 50 and 35 microns and subsequently tested in axial compression. The micro-CT scan images were analyzed to measure the crack areas along the specimen. From this analysis, the peak crack area and total crack volume along the length of the specimen was calculated. Similar to past research, as the impact energy increases, the residual compression-strength-after-impact decreases. As the impact energy increases, specimens with shrink tape sleeves had the largest increase in peak crack area and overall crack volume while specimens with full spiral sleeves had the lowest increase in peak crack area and overall crack volume. A bimodal increase is evident in the peak crack area and total crack volume over the length of the specimen where specimens impacted at 15 J (11 ft-lbs) showed the highest peak crack area across all sleeve types. There is a slight correlation between the increase in peak crack area and overall crack volume and the decrease in residual compression strength after impact. Shrink Tape, while yielding a higher quality specimen with greater compression strength prior to impact, did not protect the specimens against damage due to impact as well as other sleeve types. This was shown by the large decrease in residual compression strength after impact and increase in peak crack area and overall crack volume as the impact energy increased.

This Paper analyzes the factors influencing the labor force participation of low-income adults on public housing assistance. A quasi-experiment is designed to fulfill the purpose of measuring the magnitudes of certain attributes of given individuals, e.g. the age in influencing employment status while controlling other factors such as other personal attributes and living environments. A number of logistic regressions are performed to assist the empirical analysis. Two final models are presented while statistical results are diagnosed to ensure the reliability of findings. Based on the unique data provided by AHA (the Atlanta Housing Authority), over 70 variables are analyzed to determine their significance on influencing individuals¡¯ future employment status. Finally, we find five the most significant predictors to be the individual¡¯s current employment status, age, and income, whether one resides in a mixed-income community in comparison to living in a housing project, and whether one uses housing vouchers in comparison to living in a housing project. The individual¡¯s immediate living environment is found to play an extremely important role in shaping his/her future employment status. The results demonstrate that living in the mixed-income community as opposed to living in conventional public housing projects can boost one¡¯s odds of being employed in the future by 170% while using housing vouchers as opposed to living in traditional public housing can increase one¡¯s odds of being employed by 90%. Both statistics are significant even at the 0.001 level. Hence, our findings strongly support the view that environment matters and distressed public housing projects should be revitalized, which has been a controversial topic over years. This study introduces an innovative index system-that consists of the Family Development Index (FDI), the Neighborhood Development Index (NDI), and the Quality of Life Index (QLI)-developed by Dr. Boston to show the development of low-income adults¡¯ socio-economic status and living environments induced by the revitalization of public housing projects in Atlanta over the period of 1995-2001. Based on this innovative index system, this paper tentatively proposes a reasonable approach to separate the self-selective effect from the environmental effect in influencing the labor force participation, which has long been reckoned as a complex task in social science research. We create the Self-distinguishing Index (SDI) based on a similar mechanism by which Dr. Boston created the FDI and NDI and combine it with the FDI to generate the Self-selective Index (SSI). We also modify the NDI to serve our purpose of measuring the environmental changes at the personal level. By this method, we successfully detach the self-selective effect from the environmental effect in determining the individual¡¯s future employment status. Those two effects are found to be significant at the 0.001 level and the 0.01 level respectively. A side-finding that individuals belonging to the treatment group have significantly better odds of being employed in the future is shown as well.

Title: Comparison of the effectiveness of manual therapy and therapy using exercises in muscle postural ligations for painful neck syndromes. Objective: The main aim of this work is to compare commonly used physiotherapeutic techniques, exercise and mobilization, (manipulation) techniques in chronic, painful neck syndromes. Methods: The study involved a total of 30 probands with chronic neck pain, randomly divided into three groups of 10. In the first group the subject was health exercise, in the second group therapy with mobilization (manipulations) techniques and in the third group was a combination of both therapies. Probands were individually treated in five visits, 30 minutes for one visit. The evaluation methods were NRS, NDI and goniometry. The data was evaluated in Microsoft Office Excel. Results: The results showed that after 5 therapies there was a statistically significant reduction in pain on the NRS scale in all three groups. Within the NDI questionnaire there was a very small reduction in the ADL limitation, for all three groups, the changes were statistically significant. There were no changes in goniometry in any of the groups and changes were not statistically significant. Keywords: chronic neck pain, cervical spine, exercise, mobilization, NDI

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Title: Comparison of the effectiveness of manual therapy and therapy using exercises in muscle postural strings for painful neck syndromes. Objective: The main aim of this work is to compare the effect of active and passive approaches, combinations thereof, used in normal physiotherapy practice for painful neck syndromes. Active physiotherapy techniques represent the concept of Dr. Raševa, exercises in open and closed kinematic strings and elements of developmental kinesiology. Passive physiotherapy techniques are soft tissue techniques, mobilization and manipulation. The combination of these techniques is the application of active and passive techniques, i.e. the concept of Dr. Rašev, exercises in open and closed kinematic strings, elements of developmental kinesiology and soft tissue techniques, mobilization and manipulation. Methods: The study involved a total of 30 probands with chronic neck pain, randomly divided into three groups of 10. The first group (LTV - health exercise) included active treatment approaches, i.e. the concept of Dr. Raševa, exercises in open and closed kinematic strings and elements of developmental kinesiology. In the second group (TMT - soft tissue techniques) the contents were passive therapeutic approaches, i.e. soft tissue techniques, mobilization and manipulation....

This study investigated the effect of sensor mass, sensor location, and delamination location of different composite structures under dynamic loading. The study pertains to research of the use of accelerometers and dynamic response as a cost-effective and reliable method of structural health monitoring in composite structures. The composite structures in this research included carbon fiber plates, carbon fiber-foam sandwich panels, and carbon-fiber honeycomb sandwich panels. The composite structures were manufactured with the use of a Tetrahedron MTP-8 heat press. All work was conducted in the Cal Poly Aerospace Structures/Composites Laboratory. Initial delaminations were placed at several locations along the specimen, including the bending mode node line locations. The free vibration of the composite structure was forced through a harmonic horizontal vibration test using an Unholtz-Dickie shake system. A sinusoidal sweep input was considered for the test. The dynamic response of the composite test specimens were measured using piezoelectric accelerometers. Measurements were taken along horizontal and vertical locations on the surfaces of the composite structures. Square inch grids were marked on the surfaces to create a meshed grid system. Accelerometer measurements were taken at the center of the grids. The VIP Sensors 1011A piezoelectric accelerometer was used to measure vibration response. The measurements were then compared to response measurements taken from a PCB Piezotronics 353B04 single access accelerometer to determine the effects of sensor mass. Deviations in bending mode natural frequency and differences in mode shape amplitude became the criteria for evaluating the effect of sensor mass, sensor location, and delamination location. Changes in damping of the time response were also studied. The experimental results were compared to numerical models created using a finite element method. The experimental results and numerical values were shown to be in good agreement. The sensor mass greatly affected the accuracy and precision of vibration response measurements in the composites structures. The smaller weight and area of the VIP accelerometer helped to minimize the decrease in accuracy and precision due to sensor mass. The effect of sensor location was found to be coupled with the effect of sensor mass and the bending mode shape. The sensor location did not affect the vibration response measurements when the sensor mass was minimized. Off-center horizontal sensor placement showed the possibility of measuring vibration torsion modes. The effect of delamination changed the bending mode shape of the composite structure, which corresponded to a change in natural frequency. The greatest effect of the delamination was seen at the bending mode node lines, where the bending mode shape was most significantly affected. The effect of delamination was also dependent on the location of the delamination and the composite structure type. The results of this study provided considerations for future research of an active structural health monitoring system of composite structures using dynamic response measurements. The considerations included sensor mass reduction, sensor placement at constraints and bond areas and the presence of damping material.