Extra symmetries in the effective theory of heavy quarks

Extra symmetries are shown to exist in the effective theory of heavy quarks when both quarks and anti-quarks with the same velocity are included. These symmetries mix the quark with the anti-quark sector and they resemble axial-type of symmetries. Together with the known flavor and spin symmetries they form a $u(4)$ algebra when a single flavor is considered. It is shown that the full $U(4)$ set of symmetries breaks spontaneously down to $U(2) \otimes U(2)$. The Goldstone modes corresponding to the spontaneously broken currents are identified. Finally, the precise connection of this theory with the fundamental QCD is derived and it is investigated under some approximations. Some physical processes where these extra symmetries may be relevant are pointed out.Comment: 26 pages (two figures available upon request), tex file, UB-ECM-PF-93/

The Multifarious Role of Microglia in Brain Metastasis

The immune landscape in brain metastasis is a very heterogeneous framework. Amongst a broad plethora of cells within the tumor microenvironment, the presence of activated microglia has been perfectly described. The innate role of microglial cells is to detect and eliminate any insults that may disturb the regular behavior of the brain. As part of its defensive role, it releases pro- and anti-inflammatory cytokines that aim to modulate the inflammatory scenario at the metastatic foci. However, the long term effects that these cells may exert on the metastatic progression is not clear. One of the biggest challenges in the field is to distinguish between brain resident microglial cells and infiltrated bone-marrow derived macrophages. Part of this issue is the fact that both cell types share similar phenotypes. Current studies are based on the modulation of the immune response against cancer cells (immunotherapy). However, most of current clinical trials and newly developed drugs focus on the adaptive immune response (e.g., immune blockade check-points). Additionally, the unique structure of the central nervous system with the presence of the blood-brain barrier have hindered a significant advance in novel therapies against brain metastasis. In this manuscript, we describe current advances in characterization of tumor-associated microglia and macrophages, the importance of microglia during the anti-cancerous response, and the future direction for the development of new strategies against this complex disease

Policy and Practice Brief: PASS: SSI’s Plan for Achieving Self-Support; This Self-Directed Vocational Rehabilitation Plan is an Alternative Funding Source to Support a Range of Work Goals

This primer provides an in-depth overview of the Plan for Achieving Self-Support (PASS), a Supplemental Security Income work incentive program. Detailed is how the PASS can support self-directed vocational rehabilitation and its impact on an individual’s benefits as they progress toward their established work goal. The process for completing a PASS Application is also reviewed

Social Security Disability Insurance, Medicare And Work: A Review of the SSDI and Medicare Rules Related to Work Activity. Guidelines for Proactively Using the SSDI and Medicare Work Incentives to Help Individuals with Disabilities Maximize Independence Through Work

This policy-to-practice brief will focus on issues related to benefits and work for the SSDI beneficiary. After first explaining what SSDI is and the differences between SSDI and SSI, we will explain two historical work disincentives: the substantial gainful activity (SGA) rule and the continuing disability review (CDR). We will then explore a number of work incentives or special rules that seek to encourage work by either allowing benefits to continue for limited periods while working (trial work period (TWP), extended period of eligibility (EPE)), or allow individuals to quickly return to benefits status when a work effort stops or wage levels dip below the SGA level (expedited reinstatement). We will also explain special rules for either ignoring some short-term employment efforts (unsuccessful work attempts) or reducing countable monthly wages to be measured against the SGA amount for the year in question (impairment related work expenses, subsidies, paid time off)

Policy and Practice Brief: The Federal Earned Income Tax Credit; A Work Incentive That Puts More Money in a Paycheck and Saves on Taxes

This brief explores the Earned-Income Tax Credit which is a special tax benefit for working people who earn a low or moderate income. Reviewed are the specifics of the tax credit along with application for how it can support the career development aspirations of beneficiaries with disabilities

The Medicaid Buy-In for Working People With Disabilities: Individuals With Disabilities Can Earn Significant Wages and Qualify for This Important Health Care Benefit

This policy-to-practice brief provides an in-depth illustrated description of the Plan for Achieving Self-Support (PASS) work incentives. This brief reviews how the PASS can be used to promote a work goal; the criteria for approving a PASS; and how the PASS can be used in conjunction with other programs to promote and achieve vocational success. Throughout the brief, examples are used to illustrate principles and provide an example in the appendices to show how to propose a PASS that meets all of SSA’s criteria for approval. Extensive citations to law, regulation, and policy appear in footnotes to maximize the usefulness of this publication to benefits planners who are engaged in writing PASS proposals for individuals