Force-Free Gravitational Redshift: Proposed Gravitational Aharonov-Bohm experiment

We propose a feasible laboratory interferometry experiment with matter waves in a gravitational potential caused by a pair of artificial field-generating masses. It will demonstrate that the presence of these masses (and, for moving atoms, time dilation) induces a phase shift, even if it does not cause any classical force. The phase shift is identical to that produced by the gravitational redshift (or time dilation) of clocks ticking at the atom's Compton frequency. In analogy to the Aharonov-Bohm effect in electromagnetism, the quantum mechanical phase is a function of the gravitational potential and not the classical forces.Comment: Updated to published versio

Local and landscape-level factors influencing black tern habitat sustainability

Wetlands throughout eastern South Dakota were surveyed (1995-97) for foraging and nesting black terns (Chlidonias niger) to evaluate local and landscape factors influencing habitat suitability. We surveyed 834 randomly selected, semipermanent, and seasonal wetlands that were stratified by physiographic domain, wetland density, and wetland surface area. A discriminant function model was used in a geographic information system (GIS) to classify habitat suitability of all semipermanent wetlands in eastern South Dakota. We calculated number of suitable, protected wetlands by combining wetlands with easement and fee-title tracts in the GIS. Black terns nested in 7.8% and foraged in an additional 17.9% of semipermanent wetlands. Significant variables in the discriminant function were wetland area, total semipermanent wetland area within the wetland complex, and grassland area in the upland matrix. Black terns were an area-dependent species that occupied large (x̄ = 18.9 ha) wetlands located within high-density wetland complexes. Black terns typically occurred in wetlands within landscapes wher

Gravitational Redshift, Equivalence Principle, and Matter Waves

We review matter wave and clock comparison tests of the gravitational redshift. To elucidate their relationship to tests of the universality of free fall (UFF), we define scenarios wherein redshift violations are coupled to violations of UFF ("type II"), or independent of UFF violations ("type III"), respectively. Clock comparisons and atom interferometers are sensitive to similar effects in type II and precisely the same effects in type III scenarios, although type III violations remain poorly constrained. Finally, we describe the "Geodesic Explorer," a conceptual spaceborne atom interferometer that will test the gravitational redshift with an accuracy 5 orders of magnitude better than current terrestrial redshift experiments for type II scenarios and 12 orders of magnitude better for type III.Comment: Work in progress. 11 page

NCI First International Workshop on the Biology, Prevention, and Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation: Report from the Committee on Treatment of Relapse after Allogeneic Hematopoietic Stem Cell Transplantation

Relapse is a major cause of treatment failure after allogeneic hematopoietic stem cell transplantation (alloHSCT). Treatment options for relapse have been inadequate, and the majority of patients ultimately die of their disease. There is no standard approach to treating relapse after alloHSCT. Withdrawal of immune suppression and donor lymphocyte infusions are commonly used for all diseases; although these interventions are remarkably effective for relapsed chronic myelogenous leukemia, they have limited efficacy in other hematologic malignancies. Conventional and novel chemotherapy, monoclonal antibody therapy, targeted therapies, and second transplants have been utilized in a variety of relapsed diseases, but reports on these therapies are generally anecdotal and retrospective. As such, there is an immediate need for well-designed, disease-specific trials for treatment of relapse after alloHSCT. This report summarizes current treatment options under investigation for relapse after alloHSCT in a disease-specific manner. In addition, recommendations are provided for specific areas of research necessary in the treatment of relapse after alloHSCT

Enumerating pelvic recurrence following radical cystectomy for bladder cancer: A canadian multi-institutional study

Introduction: We aimed to enumerate the rate of pelvic recurrence following radical cystectomy at university-affiliated hospitals in Canada. Methods: Canadian, university-affiliated hospitals were invited to participate. They were asked to identify the first 10 consecutive patients undergoing radical cystectomy starting January 1, 2005, who had urothelial carcinoma stages pT3/T4 N0-2 M0. The first 10 consecutive cases starting January 1, 2005 who met these criteria were the patients submitted by that institution with information regarding tumour stage, age, number of nodes removed, and last known clinical status in regard to recurrence and patterns of failure. Results: Of the 111 patients, 80% had pT3 and 20% pT4 disease, with 62% being node-negative, 14% pN1, and 27% pN2; 57% had 10 or more nodes removed. Cumulative incidence of pelvic relapse was 40% among the entire group Conclusions: This review demonstrates a high rate of pelvic tumour recurrence following radical cystectomy for pT3/T4 urothelial cancer

The Changing of the Guard: The New American Labor Leader

This article analyzes recent changes in the leadership of international unions. There has been a trend toward leaders who are lifetime bureaucrats rather than rank-and-file members with charisma. This change toward more technocratic leadership is due to the different environment and new challenges that labor currently faces. The United Mine Workers is a good example of a union that has had many changes in the type of person who has become president, from the labor giant John L. Lewis to the 33-year-old lawyer Richard Trumka. The United Auto Workers is an example of a union whose leadership has been consistently drawn from the union hierarchy. The AFL-CIO has made a change in leadership from George Meany to the labor bureaucrat Lane Kirkland. There will probably be an increase in the number of women and minorities in top leadership positions in unions, but this will be a gradual increase.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66627/2/10.1177_000271628447300107.pd

Subunit-dependent modulation of septin assembly: Budding yeast septin Shs1 promotes ring and gauze formation

Substitution of specific terminal subunits within septin complexes and septin phosphorylation drive the formation of distinct higher-order septin assemblies in budding yeast

Bone Marrow Stromal Cells Modulate Mouse ENT1 Activity and Protect Leukemia Cells from Cytarabine Induced Apoptosis

BACKGROUND: Despite a high response rate to chemotherapy, the majority of patients with acute myeloid leukemia (AML) are destined to relapse due to residual disease in the bone marrow (BM). The tumor microenvironment is increasingly being recognized as a critical factor in mediating cancer cell survival and drug resistance. In this study, we propose to identify mechanisms involved in the chemoprotection conferred by the BM stroma to leukemia cells. METHODS: Using a leukemia mouse model and a human leukemia cell line, we studied the interaction of leukemia cells with the BM microenvironment. We evaluated in vivo and in vitro leukemia cell chemoprotection to different cytotoxic agents mediated by the BM stroma. Leukemia cell apoptosis was assessed by flow cytometry and western blotting. The activity of the equilibrative nucleoside transporter 1 (ENT1), responsible for cytarabine cell incorporation, was investigated by measuring transport and intracellular accumulation of (3)H-adenosine. RESULTS: Leukemia cell mobilization from the bone marrow into peripheral blood in vivo using a CXCR4 inhibitor induced chemo-sensitization of leukemia cells to cytarabine, which translated into a prolonged survival advantage in our mouse leukemia model. In vitro, the BM stromal cells secreted a soluble factor that mediated significant chemoprotection to leukemia cells from cytarabine induced apoptosis. Furthermore, the BM stromal cell supernatant induced a 50% reduction of the ENT1 activity in leukemia cells, reducing the incorporation of cytarabine. No protection was observed when radiation or other cytotoxic agents such as etoposide, cisplatin and 5-fluorouracil were used. CONCLUSION: The BM stroma secretes a soluble factor that significantly protects leukemia cells from cytarabine-induced apoptosis and blocks ENT1 activity. Strategies that modify the chemo-protective effects mediated by the BM microenvironment may enhance the benefit of conventional chemotherapy for patients with AML