Engraftment of allogeneic hematopoietic progenitor cells with purine analog-containing chemotherapy: harnessing graft-versus-leukemia without myeloablative therapy

The immune-mediated graft-versus-leukemia effect is important to prevent relapse after allogeneic progenitor cell transplantation. This process requires engraftment of donor immuno-competent cells. The objective of this study was to assess the feasibility of achieving engraftment of allogeneic peripheral blood or bone marrow progenitor cell after purine analog containing nonmyeloablative chemotherapy. Patients with advanced leukemia or myelodysplastic syndromes (MDS) who were not candidates for a conventional myeloablative therapy because of older age or organ dysfunction were eligible. All patients had an HLA-identical or one-antigen-mismatched related donor. Fifteen patients were treated (13 with acute myeloid leukemia and 2 with MDS). The median age was 59 years (range, 27 to 71 years). Twelve patients were either refractory to therapy or beyond first relapse. Eight patients received fludarabine at 30 mg/m2/d for 4 days with idarubicin at 12 mg/m2/d for 3 days and ara-c at 2 g/m2/d for 4 days (n = 7) or melphalan at 140 mg/m2/d (n = 1). Seven patients received 2-chloro-deoxyadenosine at 12 mg/m2/d for 5 days and ara-C 1 at g/m2/d for 5 days. Thirteen patients received allogeneic peripheral blood stem cells and 1 received bone marrow after chemotherapy. Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and methyl-prednisolone. Treatment was generally well tolerated, with only 1 death from multiorgan failure before receiving stem cells. Thirteen patients achieved a neutrophil count of greater than 0.5 x 10(9)/L a median of 10 days postinfusion (range, 8 to 17 days). Ten patients achieved platelet counts of 20 x 10(9)/L a median of 13 days after progenitor cell infusion (range, 7 to 78 days). Eight patients achieved complete remissions (bone marrow blasts were < 5% with neutrophil recovery and platelet transfusion independence) that lasted a median of 60 days posttransplantation (range, 34 to 170+ days). Acute GVHD grade > or = 2 occurred in 3 patients. Chimerism analysis of bone marrow cells in 6 of 8 patients achieving remission showed > or = 90% donor cells between 14 and 30 days postinfusion, and 3 of 4 patients remaining in remission between 60 and 90 days continued to have > or = 80% donor cells. We conclude that purine analog-containing nonmyeloablative regimens allow engraftment of HLA-compatible hematopoietic progenitor cells. This approach permits us to explore the graft-versus-leukemia effect without the toxicity of myeloablative therapy and warrants further study in patients with leukemia who are ineligible for conventional transplantation with myeloablative regimens either because of age or concurrent medical conditions.     

Structuring communication software for quality-of-serviceguarantees

We propose architectural mechanisms for structuring host communication software to provide QoS guarantees. We present and evaluate a QoS sensitive communication subsystem architecture for end hosts that provides real time communication support for generic network hardware. This architecture provides services for managing communication resources for guaranteed QoS (real time) connections, such as admission control, traffic enforcement, buffer management, and CPU and link scheduling. The architecture design is based on three key goals: maintenance of QoS guarantees on a per connection basis, overload protection between established connections, and fairness in delivered performance to best effort traffic. Using this architecture we implement real time channels, a paradigm for real time communication services in packet switched networks. The proposed architecture features a process per channel model that associates a channel handler with each established channel. The model employed for handler execution is one of “cooperative” preemption, where an executing handler yields the CPU to a waiting higher priority handler at well defined preemption points. The architecture provides several configurable policies for protocol processing and overload protection. We present extensions to the admission control procedure for real time channels to account for cooperative preemption and overlap between protocol processing and link transmission at a sending host. We evaluate the implementation to demonstrate the efficacy with which the architecture maintains QoS guarantees on outgoing traffic while adhering to the stated design goals     

Nitrous oxide emission factors in conventionally and naturally simulated cattle urine patches

Nutrient Cycling in Agroecosystems - We quantified nitrous oxide emission factors (N2O EFs) for cattle urine patches established using two simulation methods: (1) a uniformly wetted area (UWA) and...     

Crystallization kinetics of bulk amorphous Se80−xSbxTe20

Crystallization kinetics of the Se_80–x Sb _x Te₂₀ (0x9) alloys have been studied using differential scanning calorimetry. The activation energies for the glass transition and that for crystallization have been determined from the heating rate dependence of the glass transition temperature and the peak crystallization temperature. The results have been analysed using the modified Kissinger's and Matusita's equations for the non-isothermal crystallization of materials. The variation of glass transition temperature with composition suggests that a small amount of Sb ( 4 at %) leads to an increase in the chain length of Se-Te, whereas further increase in Sb atomic per cent increases the number of Se-Te chains in the alloys.     

A six-wafer combustion system for a silicon micro gas turbineengine

As part of a program to develop a micro gas turbine engine capable of producing 10-50 W of electrical power in a package less than one cubic centimeter in volume, we present the design, fabrication, packaging, and experimental test results for the 6-wafer combustion system for a silicon microengine. Comprising the main nonrotating functional components of the engine, the device described measures 2.1 cm×2.1 cm×0.38 cm and is largely fabricated by deep reactive ion etching through a total thickness of 3800 μm. Complete with a set of fuel plenums, pressure ports, fuel injectors, igniters, fluidic interconnects, and compressor and turbine static airfoils, this structure is the first demonstration of the complete hot flow path of a multilevel micro gas turbine engine. The 0.195 cm³ combustion chamber is shown to sustain a stable hydrogen flame over a range of operating mass flows and fuel-air mixture ratios and to produce exit gas temperatures in excess of 1600 K. It also serves as the first experimental demonstration of stable hydrocarbon microcombustion within the structural constraints of silicon. Combined with longevity tests at elevated temperatures for tens of hours, these results demonstrate the viability of a silicon-based combustion system for micro heat engine applications     

Policy-based Diffserv on Internet servers: the AIX approach

The Internet infrastructure must evolve from best-effort service to meet the needs of different customers and applications. With Internet traffic differentiation, service providers can support a range of offerings, such as loss or delay bounds and network bandwidth allocation, to meet different performance requirements. The differentiated services (Diffserv) architecture provides a scalable approach, in which network access (or edge) devices aggregate traffic flows onto provisioned pipes that traverse a streamlined network core. We have identified the key requirements for provisioning Diffserv functions on Internet servers. Based on these requirements, we have implemented, and deployed, a policy-based architecture on IBM's AIX operating system that provides Diffserv services to both QoS-aware and -unaware applications     

A low power,temperature compensated,robust design of CS amplifier in nanoscale regime

Microsystem Technologies - A low power, temperature compensated, robust design of CS amplifier is proposed in this paper. A new voltage reference is introduced to enhance reliability of the design...     

Introduction to the Works of Rodney C. Wingrove: Engineering Approaches to Macroeconomic Modeling

A continuous-time control model was formulated and fitted to macroeconomic data by an expert control engineer who worked at NASA-AMES in the 1980s, Rodney C. Wingrove. Two articles were prepared and made available to the aerospace industry at that time, however the authors feel that wider distribution of his study posthumously is warranted at this time. This introduction to the two Wingrove articles that follow provides background information on the technologies Wingrove was working with, as well as subsequent developments in both macroeconomic and engineering modeling and analysis technology. Our purpose is to stimulate further research along the same lines which can potentially lead to structural and/or policy rule improvements that can prevent the extremely turbulent abberations that have been seen in recent years, and promote steady growth with low inflation and low unemployment in a sustainable way. Of particular concern is the exploding national debt problem.     

Current issues and emerging trends in supply chain management: an editorial perspective

Due to the ever-changing dynamics of today's global market place, it is necessary to examine upcoming future trends that may impact businesses. Supply chains are a valuable component of all business planning, and hence, they must be continuously monitored. This paper reflects on the views and contributions of various authors writing on the crucial issue of managing supply chains. Specifically, topics such as relationship quality, performance, integration, responsiveness, risk management strategies, agility, and incentive systems in supply chains are addressed.