Torsion of Exterior Girders of a Steel Girder Bridge During Concrete Deck Placement Loads: Field Test Report

This report is the second part of a two part report. The first part is written and developed as a design aid to determine the torsion acting on outside steel bridge girders during concrete deck placement. This second part reports results of measurements taken from two bridges. The first bridge is located at K-10 highway over I-70 between Lawrence and Topeka, Kansas. The second bridge is located on southbound I-635 highway over Swartz Road in Kansas City, Kansas. During bridge construction, deck overhang loads occur on steel plate or rolled beam girders and are supported by cantilever brackets. In addition to supporting the weight of the placement screed, these brackets must also support the weight of the additional construction loads. The vertical loads applied on the deck are eccentric and generate large torsional moments at the intervals between cross bracing. The result of this loading effect is torsional moments that generate a combination of longitudinal stresses and loads from the cantilever brackets. Strain gages were installed on the Swartz Road bridge to measure these overhang loads. A "Multiframe 4D" computer model was made to compare the results measured in the field, with AISC recommendations, and with TAEG ( Torsional Analysis of Exterior Girders) results. The screed loads measured from the static load runs and analytical model were based on the locations of bogey and gang vibrators. In the analytical model, the loads were moved across the beam at quarter points beginning at midspan, then tabulated and plotted alongside the field results. After all of the moments representing the various load cases were compiled, an influence diagram was constructed from the loads measured in the field and the analytical model. Loads were analyzed for two cases using the AISC method outlined in the "Design for Concrete Overhang Loads". The first load case represented the static field test while the second represented the results measured the day of concrete placement. The same wheel loading for the analytical model was used for the AISC calculations. In some instances, the strains measured on the Swartz Road bridge were small. In these situations it can be difficult to guarantee the sensitivity and output of gage readings, however, the major axis moments measured on the Swartz Road bridge during static load testing were almost identical to the moments calculated with the Multiframe analysis. This shows that the loads that were used and how they were distributed in the Multiframe analysis were close to actual field conditions. This also shows consistent. and accurate behavior of the strain gages. No significant differences were found with the moments measured from the static load runs where blocking had been removed. More blocking had been provided than what was needed on the Swartz Road bridge, however, when concrete and live loads are added, the change in load response should be greater. Surveying prisms were used to measure deflections during the load tests. The recorded and predicted maximum vertical deflections on the Swartz Road bridge were consistently ~lose for all load runs. Horizontal deflections were not observed at any location. The Multiframe model used to calculate torsional bending did match closely with the moments measured in the field at midpoint between stiffeners but varied greatly between measured and analytical results for endpoint locations. The computer model used to calculate torsional bending did not match as closely with the moments measured in the field. The difference between measured and analytical results varied for maximum values but was in relative agreement for the trends of the moments. Most of the differences can be attributed to the lateral stiffness provided by a combination of deck formwork and a portion of concrete deck in place in the Northbound lanes. Unfortunately, the loose play of the form work connections to the girder makes the lateral stiffness difficult to measure. Some of the differences in the torsional moments that were calculated using the Multiframe model and the TAEG program can be attributed to some basic model assumptions. The Multiframe analysis was based on a non-prismatic girder section that was continuous over diaphragm locations. The T AEG program assumes a three span, prismatic member. A comparison of torsional moments calculated by T AEG show a large difference in results from field measurements, the torsional model, and AISC calculations. In some cases the differences are small and in others they are significant. For the static field tests and the Multiframe torsion models, the trends show close similarity, however the maximum loads for all locations do vary. The TAEG program was always conservative in comparison to the field results and the multiframe model. Since the T AEG program is intended to be used as an in-house design aid, this conservative approach is regarded as positive

Analysis of multiply spliced transcripts in lymphoid tissue reservoirs of rhesus macaques infected with RT-SHIV during HAART.

Highly active antiretroviral therapy (HAART) can reduce levels of human immunodeficiency virus type 1 (HIV-1) to undetectable levels in infected individuals, but the virus is not eradicated. The mechanisms of viral persistence during HAART are poorly defined, but some reservoirs have been identified, such as latently infected resting memory CD4⁺ T cells. During latency, in addition to blocks at the initiation and elongation steps of viral transcription, there is a block in the export of viral RNA (vRNA), leading to the accumulation of multiply-spliced transcripts in the nucleus. Two of the genes encoded by the multiply-spliced transcripts are Tat and Rev, which are essential early in the viral replication cycle and might indicate the state of infection in a given population of cells. Here, the levels of multiply-spliced transcripts were compared to the levels of gag-containing RNA in tissue samples from RT-SHIV-infected rhesus macaques treated with HAART. Splice site sequence variation was identified during development of a TaqMan PCR assay. Multiply-spliced transcripts were detected in gastrointestinal and lymphatic tissues, but not the thymus. Levels of multiply-spliced transcripts were lower than levels of gag RNA, and both correlated with plasma virus loads. The ratio of multiply-spliced to gag RNA was greatest in the gastrointestinal samples from macaques with plasma virus loads <50 vRNA copies per mL at necropsy. Levels of gag RNA and multiply-spliced mRNA in tissues from RT-SHIV-infected macaques correlate with plasma virus load

Critical Friends Group: the effects in an elementary school setting

The purpose of this study was to explore the effects of a Critical Friends Group on classroom practices and collaboration when implemented within an elementary school setting. Nine certified elementary school teachers in a southeastern North Carolina elementary school were taught the Critical Friends Group process in order to participate in focused observations of fellow group members and discussed findings with peers. Participants were led by a coach every two weeks to discuss a topic in education and other related findings. Video taped meetings, written reflection questions, and raw data from teacher observations were collected, and analyzed, and examined for themes relevant to the collaboration process. Major themes were support and trust, creating professional growth through the Critical Friends Group, elaborate foci of observations, and relevant strategies shared to improve the teaching practice. Data analysis revealed that when teachers voluntarily collaborate on focused areas of observation, production level of strategies to implement within the classroom increased. Data also revealed that collaboration amongst peers of different grade levels created trust that allowed teachers to discuss issues in a more comfortable level. Recommendations for implementing a Critical Friends Group within an elementary school are provided

Evidence for ACTN3 as a genetic modifier of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is characterized by muscle degeneration and progressive weakness. There is considerable inter-patient variability in disease onset and progression, which can confound the results of clinical trials. Here we show that a common null polymorphism (R577X) in ACTN3 results in significantly reduced muscle strength and a longer 10\u2009m walk test time in young, ambulant patients with DMD; both of which are primary outcome measures in clinical trials. We have developed a double knockout mouse model, which also shows reduced muscle strength, but is protected from stretch-induced eccentric damage with age. This suggests that \u3b1-actinin-3 deficiency reduces muscle performance at baseline, but ameliorates the progression of dystrophic pathology. Mechanistically, we show that \u3b1-actinin-3 deficiency triggers an increase in oxidative muscle metabolism through activation of calcineurin, which likely confers the protective effect. Our studies suggest that ACTN3 R577X genotype is a modifier of clinical phenotype in DMD patients

Chain gangs, roads, and reform in North Carolina, 1900-1935

For the first three decades of the twentieth century, dozens of predominantly black county chain gangs proliferated across North Carolina. The camps existed solely to build county roads, a consequence of efforts by the North Carolina Good Roads Association (NCGRA) to create a network of reliable roads in order to improve the state's economic prospects. As a self-proclaimed progressive non-governmental group, the NCGRA promoted reliance on chain gang labor as a reform that would profit the state and uplift the convicts. While convicts built roads that helped position North Carolina at the forefront of economic progress in the South, rather than benefitting the prisoners, the chain gangs became sites of abuse and degradation. Chain gang convicts often resisted the inhumane conditions they endured, relying heavily on their connection to the State Board of Charities and Public Welfare (SBC), a state agency whose official duties included inspecting penal institutions and making recommendations for their improvement. With the SBC's assistance, convicts pushed for investigations into the camps and conveyed their messages to powerful politicians and newspapermen who publicized their struggle. Convicts helped shape reformers' debates as they risked severe punishment and even death by engaging in protest and resistance against the brutality of the camps. By the 1930s, their pursuit of humane treatment came to influence state level efforts to rectify the abusive conditions so long associated with the county chain gangs

Two stories

The purpose of this thesis is, quite simply, to tell two stories. They are stories I thought worth telling, and they are told as I believe they should be told. Each centers about a single character because I believe that people are the essence of fiction. It will perhaps be most effective to write about the stories Individually, Inasmuch as talking generally about fiction—its goals and methods--seems a sure and ready way to make oneself foolish. Indeed, talking too much about even the individual ones of one's stories is a way to seem foolish. If what one feels about the story could be summed up in a quick sentence or two, then there would have been no point ever in writing the story

Sequential emergence and clinical implications of viral mutants with K70E and K65R mutation in reverse transcriptase during prolonged tenofovir monotherapy in rhesus macaques with chronic RT-SHIV infection.

BackgroundWe reported previously on the emergence and clinical implications of simian immunodeficiency virus (SIVmac251) mutants with a K65R mutation in reverse transcriptase (RT), and the role of CD8+ cell-mediated immune responses in suppressing viremia during tenofovir therapy. Because of significant sequence differences between SIV and HIV-1 RT that affect drug susceptibilities and mutational patterns, it is unclear to what extent findings with SIV can be extrapolated to HIV-1 RT. Accordingly, to model HIV-1 RT responses, 12 macaques were inoculated with RT-SHIV, a chimeric SIV containing HIV-1 RT, and started on prolonged tenofovir therapy 5 months later.ResultsThe early virologic response to tenofovir correlated with baseline viral RNA levels and expression of the MHC class I allele Mamu-A*01. For all animals, sensitive real-time PCR assays detected the transient emergence of K70E RT mutants within 4 weeks of therapy, which were then replaced by K65R mutants within 12 weeks of therapy. For most animals, the occurrence of these mutations preceded a partial rebound of plasma viremia to levels that remained on average 10-fold below baseline values. One animal eventually suppressed K65R viremia to undetectable levels for more than 4 years; sequential experiments using CD8+ cell depletion and tenofovir interruption demonstrated that both CD8+ cells and continued tenofovir therapy were required for sustained suppression of viremia.ConclusionThis is the first evidence that tenofovir therapy can select directly for K70E viral mutants in vivo. The observations on the clinical implications of the K65R RT-SHIV mutants were consistent with those of SIVmac251, and suggest that for persons infected with K65R HIV-1 both immune-mediated and drug-dependent antiviral activities play a role in controlling viremia. These findings suggest also that even in the presence of K65R virus, continuation of tenofovir treatment as part of HAART may be beneficial, particularly when assisted by antiviral immune responses

KOI-3890: A high mass-ratio asteroseismic red-giant++M-dwarf eclipsing binary undergoing heartbeat tidal interactions

KOI-3890 is a highly eccentric, 153-day period eclipsing, single-lined spectroscopic binary system containing a red-giant star showing solar-like oscillations alongside tidal interactions. The combination of transit photometry, radial velocity observations, and asteroseismology have enabled the detailed characterisation of both the red-giant primary and the M-dwarf companion, along with the tidal interaction and the geometry of the system. The stellar parameters of the red-giant primary are determined through the use of asteroseismology and grid-based modelling to give a mass and radius of $M_{\star}=1.04\pm0.06\;\textrm{M}_{\odot}$ and $R_{\star}=5.8\pm0.2\;\textrm{R}_{\odot}$ respectively. When combined with transit photometry the M-dwarf companion is found to have a mass and radius of $M_{\mathrm{c}}=0.23\pm0.01\;\textrm{M}_{\odot}$ and $R_{\mathrm{c}}=0.256\pm0.007\;\textrm{R}_{\odot}$. Moreover, through asteroseismology we constrain the age of the system through the red-giant primary to be $9.1^{+2.4}_{-1.7}\;\mathrm{Gyr}$. This provides a constraint on the age of the M-dwarf secondary, which is difficult to do for other M-dwarf binary systems. In addition, the asteroseismic analysis yields an estimate of the inclination angle of the rotation axis of the red-giant star of $i=87.6^{+2.4}_{-1.2}$ degrees. The obliquity of the system\textemdash the angle between the stellar rotation axis and the angle normal to the orbital plane\textemdash is also derived to give $\psi=4.2^{+2.1}_{-4.2}$ degrees showing that the system is consistent with alignment. We observe no radius inflation in the M-dwarf companion when compared to current low-mass stellar models.Comment: 11 pages, 5 figures, accepted for publication in MNRA

Semiconductive and Photoconductive Properties of the Single Molecule Magnets Mn12_{12}-Acetate and Fe8_8Br8_8

Resistivity measurements are reported for single crystals of Mn$_{12}$-Acetate and Fe$_8$Br$_8$. Both materials exhibit a semiconductor-like, thermally activated behavior over the 200-300 K range. The activation energy, $E_a$, obtained for Mn$_{12}$-Acetate was 0.37 $\pm$ 0.05 eV, which is to be contrasted with the value of 0.55 eV deduced from the earlier reported absorption edge measurements and the range of 0.3-1 eV from intramolecular density of states calculations, assuming $2E_a$= $E_g$, the optical band gap. For Fe$_8$Br$_8$, $E_a$ was measured as 0.73 $\pm$ 0.1 eV, and is discussed in light of the available approximate band structure calculations. Some plausible pathways are indicated based on the crystal structures of both lattices. For Mn$_{12}$-Acetate, we also measured photoconductivity in the visible range; the conductivity increased by a factor of about eight on increasing the photon energy from 632.8 nm (red) to 488 nm (blue). X-ray irradiation increased the resistivity, but $E_a$ was insensitive to exposure.Comment: 7 pages, 8 figure

Anatomy of a Dansgaard-Oeschger warming transition: High-resolution analysis of the North Greenland Ice Core Project ice core

Large and abrupt temperature oscillations during the last glacial period, known as Dansgaard‐Oeschger (DO) events, are clearly observed in the Greenland ice core record. Here we present a new high‐resolution chemical (2 mm) and stable isotope (20 mm) record from the North Greenland Ice Core Project (NGRIP) ice core at the onset of one of the most prominent DO events of the last glacial, DO‐8, observed ∼38,000 years ago. The unique, subannual‐resolution NGRIP record provides a true sequence of change during a DO warming with detailed annual layer counting of very high depth resolution geochemical measurements used to determine the exact duration of the transition. The continental ions, indicative of long‐range atmospheric loading and dustiness from East Asia, are the first to change, followed by the snow accumulation, the moisture source conditions, and finally the atmospheric temperature in Greenland. The sequence of events shows that atmospheric and oceanic source and circulation changes preceded the DO warming by several years