2,925 research outputs found
Electric Cooperatives and the Digital Divide: Helping Connect Rural Americans to 21st Century Opportunity
The task of bringing high speed Internet to America's rural communities remains a challenging and painfully unfinished one, aggravating the existing economic and social divides these communities face. To help address this challenge, certain rural energy cooperatives (RECs)—including three in Michigan—have begun deploying high-speed fiber optic networks to better connect their members. This project examines the experience of these pioneers and related factors to develop a body of information, analysis, and recommendations to inform strategies aimed at expanding broadband, and the benefits it can bring to underserved rural communities
Aligning Resources to Connect Rural Michigan to Pandemic-Ready Broadband Networks
Following up on his REI co-learning plan examining issues and strategies related to the potential for rural electric cooperatives (RECs) to help bridge the digital divide, Mitchell’s Innovation Fellowship will focus on aligning a broad range of stakeholder resources to more effectively expand broadband and its benefits in rural Michigan. This will include the state’s RECs as well as its regional planning association (RPOs), local governments and community anchor institutions (CAIs). The project will also support efforts to effectively leverage the expertise and longstanding Michigan-focused experience of Connected Nation Michigan, as well as the recently launched Michigan Moonshot project. The Moonshot project is a statewide effort to expand rural broadband led by Merit Network, a nonprofit university-owned network operator that has been providing high-performance communication services to the state’s educational and CAI community for more than 50 years
Cadaveric renal transplantation at the University of Pittsburgh: a two and one-half-year experience with the point system.
From January 1, 1986 to July 30, 1988, 530 consecutive cadaver kidney transplantations were performed with patient selection by a point system that took into account time awaiting an organ, donor-recipient matching, degree of presensitization, and some less important factors. The effect of the system was to diminish judgmental factors in case selection which in the past, had probably operated to the disadvantage of "undesirable" potential recipients, including older ones. Primary 1-year graft survival (74%) and graft survival after retransplantation (71%) were lower than in the earlier time. However, the results with triple-drug therapy using CsA, AZA and P demonstrated 88% 1-year graft survival for primary graft recipients and 74% in highly sensitized patients, with comparable patient mortality. These latter observations provide some assurance that the concepts of equitable access and efficient utilization of a scarce resource are not mutually exclusive
A signaling pathway leading to metastasis is controlled by N-cadherin and the FGF receptor
The intracellular signaling events causing tumor cells to become metastatic are not well understood. N-cadherin and FGF-2 synergistically increase migration, invasion, and secretion of extracellular proteases in breast tumor cells. Here, we define a metastatic signaling cascade activated by N-cadherin and FGF-2. In the presence of N-cadherin, FGF-2 caused sustained activation of the MAPK-ERK pathway, leading to MMP-9 gene transcription and cellular invasion. N-cadherin prevented the FGF receptor (FGFR) from undergoing ligand-induced internalization, resulting in increased FGFR-1 stability. Association of FGFR-1 with N-cadherin was mediated by the first two Ig-like domains of FGFR-1. These results suggest that protection of the FGFR-1 from ligand-induced downregulation by N-cadherin enhances receptor signaling and provides a mechanism by which tumor cells can acquire metastatic properties
Randomized trial of FK 506/prednisone vs FK 506/azathioprine/prednisone after renal transplantation: preliminary report.
FK 506 was used as a primary immunosuppressive agent in 125 cases of renal transplantation in a randomized trial comparing FK 506/prednisone with FK 506/azathioprine/prednisone. With a mean follow-up of 5.5 +/- 2.5 months, there has been a 6-month actuarial patient survival of 99% and graft survival of 88%. There is no difference thus far between the two-drug and three-drug groups, although there may be less rejection and diabetes in the three-drug group. These results suggest that FK 506 is a useful immunosuppressive agent in kidney transplantation
Tendinosis develops from age- and oxygen tension-dependent modulation of Rac1 activity.
Age-related tendon degeneration (tendinosis) is characterized by a phenotypic change in which tenocytes display characteristics of fibrochondrocytes and mineralized fibrochondrocytes. As tendon degeneration has been noted in vivo in areas of decreased tendon vascularity, we hypothesized that hypoxia is responsible for the development of the tendinosis phenotype, and that these effects are more pronounced in aged tenocytes. Hypoxic (1% O2 ) culture of aged, tendinotic, and young human tenocytes resulted in a mineralized fibrochondrocyte phenotype in aged tenocytes, and a fibrochondrocyte phenotype in young and tendinotic tenocytes. Investigation of the molecular mechanism responsible for this phenotype change revealed that the fibrochondrocyte phenotype in aged tenocytes occurs with decreased Rac1 activity in response to hypoxia. In young hypoxic tenocytes, however, the fibrochondrocyte phenotype occurs with concomitant decreased Rac1 activity coupled with increased RhoA activity. Using pharmacologic and adenoviral manipulation, we confirmed that these hypoxic effects on the tenocyte phenotype are linked directly to the activity of RhoA/Rac1 GTPase in in vitro human cell culture and tendon explants. These results demonstrate that hypoxia drives tenocyte phenotypic changes, and provide a molecular insight into the development of human tendinosis that occurs with aging
A prospective randomized trial of FK506-based immunosuppression after renal transplantation
A group of 204 adult patients was entered into a prospective, randomized trial comparing FK506/pred-nisone with FK506/azathioprine/prednisone after renal transplantation between August 1, 1991 and October 11,1992. The purpose of the study was to see if the addition of azathioprine would reduce the incidence of rejection and improve graft survival. The recipient population was unselected, with 61 (30%) patients undergoing retransplantation, 37 (18%) having a panel-reactive antibody greater than 40%, and 33 (16%) over 60 years of age. The mean recipient age was 43.8±13.7 years (range 17.6-78). The mean donor age was 34.0±20.1 years (range 0.3-75); 13% of the cadaveric kidneys were from pediatric donors less than 3 years of age and were transplanted en bloc. The mean cold ischemia time was 31.4±8.4 hr. Living donors were the source of 13% of the kidneys. The mean follow-up was 22±4 months (range 12-29). Overall one-year actual patient survival was 94%. Overall one-year actual graft survival was 87%. Patients starting on double therapy had a one-year actual patient survival of 96% and a one-year actual graft survival of 92%. Patients starting on triple therapy had a one-year actual patient survival of 91% (P=ns compared with double therapy), and a one-year actual graft survival of 82% (P<0.02, compared with double therapy). Overall results with first cadaver transplants included a one-year actual patient survival of 94% and one-year actual graft survival of 88%, with no differences between double and triple therapy. The overall incidence of rejection was 48%, with 54% in the double therapy group and 41% in the triple therapy group (P<.07). The incidence of steroid-resistant rejection requiring antilymphocyte therapy (OKT3 or ATGAM) was 13%, and was not different between the double and triple therapy groups. The mean serum creatinine was 1.8±0.8 mg/dl. The mean BUN was 33±21 mg/dl, with no significant difference between the therapy groups. The mean serum cholesterol was 192 ±49 mg/dl. A total of 56% of the patients are off prednisone, and 35% of the patients are not taking any antihypertensive medications. Other complications included cytomegalovirus—14%; new-onset diabetes—16% (half of which was reversible); and posttransplant lymphoproliferative disorder—1%. There was a high incidence of crossover between the two groups, 27% of the patients in the double therapy group requiring the addition of azathioprine, and 45% of the patients in the triple therapy group requiring its discontinuation (usually tempoгагу). These results show that FK506 is an excellent immunosuppressive agent after renal transplantation and that azathioprine is not routinely effective as a third agent. A high quality of life resulted from the ability to use no (56%) or low-dose maintenance steroids. © 1995 by Williams and Wilkins
FK506 IN PEDIATRIC KIDNEY-TRANSPLANTATION - PRIMARY AND RESCUE EXPERIENCE
Between December 14, 1989, and December 17, 1993,43 patients undergoing kidney transplantation alone at the Children’s Hospital of Pittsburgh received FK506 as the primary immunosuppressive agent. The mean recipient age was 10.2 ± 4.8 years (range 0.7–17.4), with 7 (16%) children under 5 years of age and 2 (5%) under 2 years of age. Fifteen (35%) children underwent retransplantation, and 5 (12%) had a panel reactive antibody level greater than 40%. Twenty-two (51%) cases were with cadaveric donors, and 21 (49%) were with living donors. The mean follow-up is 25 ± 14 months. There were no deaths. One and three year actuarial graft survival was 98% and 85%. The mean serum creatinine and BUN were 1.2 ± 0.6 mg/dl and 26 ± 11 mg/dl; the calculated creatinine clearance was 75 ± 23 ml/min/1.73 m(2). Twenty-four (62%) patients have been successfully withdrawn from steroids, and 24 (62%) require no anti-hypertensive medication. Improved growth was seen, particularly in pre-adolescent children off steroids. Between July 28, 1990, and December 2, 1993, 24 children were referred for rescue therapy with FK506, 14.6 ± 16.4 months (range 1.1–53.2) after transplantation. Nineteen (79%) were referred because of resistant rejection; 4 (17%) were referred because of proteinuria; 1 (4%) was switched because of steroid-related obesity. There were no deaths. One and two year graft survival was 75% and 68%. Seventeen (71%) patients were successfully rescued, including 1 of 2 patients who arrived on dialysis. Four (24%) of the successfully rescued patients were weaned off steroids. While not without side effects, which include nephrotoxicity, neurotoxicity, diabetogenicity, and viral complications, FK506 appears to be an effective immunosuppressive agent for both primary and rescue therapy after kidney transplantation. Its steroid-sparing qualities may be of particular importance in the pediatric population
Compositional Explanation of Types and Algorithmic Debugging of Type Errors
The type systems of most typed functional programming languages are based on the Hindley-Milner type system. A practical problem with these type systems is that it is often hard to understand why a program is not type correct or a function does not have the intended type. We suggest that at the core of this problem is the difficulty of explaining why a given expression has a certain type. The type system is not defined compositionally. We propose to explain types using a variant of the Hindley-Milner type system that defines a compositional type explanation graph of principal typings. We describe how the programmer understands types by interactive navigation through the explanation graph. Furthermore, the explanation graph can be the foundation for algorithmic debugging of type errors, that is, semi-automatic localisation of the source of a type error without even having to understand the type inference steps. We implemented a prototype of a tool to explore the usefulness of the proposed methods
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