Gravitational self-force in nonvacuum spacetimes

The gravitational self-force has thus far been formulated in background spacetimes for which the metric is a solution to the Einstein field equations in vacuum. While this formulation is sufficient to describe the motion of a small object around a black hole, other applications require a more general formulation that allows for a nonvacuum background spacetime. We provide a foundation for such extensions, and carry out a concrete formulation of the gravitational self-force in two specific cases. In the first we consider a particle of mass $m$ and scalar charge $q$ moving in a background spacetime that contains a background scalar field. In the second we consider a particle of mass $m$ and electric charge $e$ moving in an electrovac spacetime. The self-force incorporates all couplings between the gravitational perturbations and those of the scalar or electromagnetic fields. It is expressed as a sum of local terms involving tensors defined in the background spacetime and evaluated at the current position of the particle, as well as tail integrals that depend on the past history of the particle. Because such an expression is rarely a useful starting point for an explicit evaluation of the self-force, we also provide covariant expressions for the singular potentials, expressed as local expansions near the world line; these can be involved in the construction of effective extended sources for the regular potentials, or in the computation of regularization parameters when the self-force is computed as a sum over spherical-harmonic modes.Comment: 20 pages, no figure

A scientometric look at scholory cooperation between Europe and Israel. An explorative study of a changing landscape.

Cooperation; Studies;

Dwyer Google Migration

The IT staff at Dwyer Instruments encountered several issues when switching to use Google’s business technology services. These problems included lack of a button to open a new email draft with a PDF already attached, the timestamp function in Google Sheets displaying the current time instead of the time it was entered, duplicate Google Sheets spreadsheets not maintaining protected ranges, lack of a timeline chart in Google Sheets, inability to save Gmail searches, lack of event templates in Google Calendar, and lack of a workflow management tool in Google’s business technology suite. On site personnel were asked to communicate what would help smooth the transition to the G Suite. One challenge encountered was the difficulty in publishing G-Suite add-ons to Google’s online marketplace. Another challenge is presented by the lack of examples of G-Suite add-ons. This makes it tough to create add-ons since there are few resources to go off of. A G-Suite add-on was developed to create an in-page side window in Gmail and Drive to allow attachments from selected conversations or Drive files to be attached and sent with an email. A Google Sheets add-on was also developed in order to insert the current time into a selected cell. While some needs remain outstanding, but the project made significant progress toward solving some of their IT issues

TOXOPLASMA GONDII IN U.S. SWINE OPERATIONS: AN ASSESSMENT OF MANAGEMENT FACTORS

Sera from hogs were analyzed using the modified direct agglutination test (MAT). Serum samples were collected from sows which were part of the National Animal Health Monitoring System (NAHMS) swine survey. The blood sera on file represented 394 randomly selected hog farms throughout the United States. Additionally, the NAHMS survey included information on type of production facilities and level of cat, dog, or bird access to the facilities. Of the sows tested 19 percent tested positive for toxoplasmosis. This study showed a positive relationship between sows or herds testing positive for Toxoplasma gondii and three factors: 1) method of rodent control, 2) type of production facility, and 3) access of certain animals (cats, dogs, birds) to production facilities. These data indicate that it will be difficult to eliminate T. gondii from swine herds which allow cat or dog access to facilities. Use of cats as a method of rodent control should be discouraged. We found a strong association between use of "bait only" for rodent control and the herd testing negative as compared to the use of "cats only" for rodent control. Greater industry awareness is needed for methods of rodent control through the use of baits. Sows in herds where female replacements were raised internally were significantly more likely to test positive for toxoplasmosis. Sows in confinement facilities had a significantly lower prevalence of Toxoplasma gondii. Herds testing positive were significantly smaller than those which were negative. In general, there were not any regional differences in prevalence rates. Sows testing positive did not have a reduced level of productivity.

MOLECULAR ADAPTATION TO ANTI-CANCER CHEMOTHERAPY IN LEUKEMIA

Drug resistance to anti-cancer chemotherapy is a significant barrier to the treatment of leukemia patients. Many times, resistance results from molecular adaptation to drug exposure, such as genetic mutation of key enzymes, up-regulation of pro-survival compensatory signaling pathways, and altered drug transport. In this dissertation, we describe two examples of molecular drug resistance in cell models of 1) Ara-C-resistant acute lymphoblastic leukemia (ALL) and 2) imatinib-resistant chronic myelogenous leukemia (CML). First, we determined that nucleoside transport is deficient in the Ara-C-resistant T-cell ALL CCRF-CEM cell line (Ara-C/8C) in comparison to drug-sensitive parental CCRF-CEM cells. Further study found a single point mutation in glycine residue 24 (G24) within equilibrative nucleoside transporter 1 (ENT1), a protein responsible for nucleoside uptake in these cells. Therefore, we tested the ability of G24A, G24R, and G24E ENT1 mutants to transport uridine and Ara-C and localize to the plasma membrane. Our data suggest that mutation of G24 disrupts ENT1 transport activity without altering localization; thus, expression of mutant ENT1 may confer Ara-C resistance in CCRF-CEM AraC/8C cells. In the second portion of the dissertation, we studied the role of Lyn tyrosine kinase (Lyn) in imatinib-resistant CML MYL-R cells. In comparison to drug-sensitive parental MYL cells, Lyn was hyper-active, and loss of Lyn activity sensitized cells to imatinib treatment. We determined that Lyn inhibited miR181 microRNA (miRNA) expression in MYL-R cells at the transcriptional level. In addition, we determined that miR181b targeted the 3' UTR of Mcl-1, a pro-survival protein associated with drug-resistance, resulting in Mcl-1 degradation. Thus, we defined a molecular signaling axis by which Lyn may confer drug resistance in imatinib-resistant CML. We attempted to elucidate the mechanism of Lyn-dependent miR181 expression and found that 1) the transcription factors CREB and STAT5 do not regulate miR181a/b and 2) Lyn may regulate miR181c/d expression through modification of histone acetylation. These studies contribute to our knowledge of drug resistance mechanisms in leukemia and provide novel biomarkers for the identification of drug-resistant cancer.Doctor of Philosoph

CIRCUIT DYNAMICS UNDERLYING CONTROL OF DOPAMINE NEURON ACTIVITY BY THE NUCLEUS REUNIENS OF THE MIDLINE THALAMUS

The circuitry mediating top-down control of dopamine (DA) neurons in the ventral tegmental area (VTA) is exceedingly complex. Characterizing these networks will be critical to our understanding of fundamental behaviors, such as motivation and reward processing, as well as several disease states. Previous work suggests that the medial prefrontal cortex (mPFC) exerts a profound influence on VTA DA neuron firing. Recently, our group reported that inhibition of the infralimbic subdivision of the medial prefrontal cortex (ilPFC) increases the proportion of VTA DA neurons that are spontaneously active (i.e., “population activity”) and that this effect depends on activity in the ventral subiculum of the hippocampus (vSub). However, there is no direct projection from the mPFC to the vSub. Anatomical evidence suggests that communication between the two structures is mediated by the nucleus reuniens of the midline thalamus (RE). The work presented in this dissertation aims to determine if RE controls VTA DA neuron firing and to describe the circuits underlying ilPFC-RE communication. In Chapter 2, we present findings demonstrating that RE can drive VTA DA neuron firing by engaging vSub. In addition, we show that ilPFC opposes this effect, likely via input to RE in the form of feedforward inhibition from TRN. In Chapter 3, we present findings that characterize the diverse array of RE neuron firing patterns in an intact preparation and describe the circuit dynamics underlying projections from ilPFC to RE. These studies suggest that ilPFC exerts control of RE neuron firing pattern through direct, monosynaptic connections and via the thalamic reticular nucleus (TRN). Overall, the studies described in this dissertation reveal a novel role for a corticothalamic circuit including the ilPFC, RE, and vSub in controlling VTA DA neuron firing and confirm that corticothalamic input from ilPFC to RE can modulate RE neuron firing pattern in nuanced and complex ways. In addition, these findings provide a plausible circuit basis for various behavioral phenomena observed in schizophrenia, and could help inform the development of novel treatments

Pile Driving Adjacent to Municipal Drinking Water Storage Facility

An unexpected response occurred as piles were driven within 3 feet of the west wall of an existing municipal drinking water storage reservoir. Being located in a confined urban space, the expansion of the parking garage at a facility on the south end of Lake Michigan required the installation of 122 steel H-piles as close as 3 feet to the reservoir. Historically, structures on the site were supported on either shallow spread footings or H-piles driven to bedrock. At the contractor’s suggestion, considerable project savings were achieved by driving the H-piles to an extremely hard clay layer (“Chicago hardpan”) above the bedrock. Pressuremeter testing, and static and dynamic load testing of the H-piles were completed as part of the project testing program. Both the horizontal and vertical movements of the reservoir wall were monitored during pile driving. The paper presents the design parameter changes, static and dynamic pile testing, and vibration monitoring for construction of the multi-level parking structure adjacent to the 8 million gallon drinking water storage facility. The vertical movements of the tank’s west wall and the corrective actions taken after water began seeping from pre-existing cracks in the tanks wall are the focus of the case study