Plasmoid impacts on neutron stars and highest energy cosmic rays

Particle acceleration by electrostatic polarization fields that arise in plasmas streaming across magnetic fields is discussed as a possible acceleration mechanism of highest-energy cosmic rays. Specifically, plasmoids arising in planetoid impacts onto neutron star magnetospheres are considered. We find that such impacts at plausible rates may account for the observed flux and energy spectrum of the highest energy cosmic rays.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Lett., uses REVTE

On a mechanism of highest-energy cosmic ray acceleration

A recently proposed mechanism of acceleration of highest energy cosmic rays by polarization electric fields arising in plasmoids injected into neutron star magnetospheres is discussed.Comment: 6 pages, to appear in Proc. of 20th Texas Symposium on Relativistic Astrophysics, uses aipproc (included

Microwave Electronics

Contains reports on three research projects.Lincoln Laboratory (Purchase Order DDL-B222)United States Department of the ArmyUnited States Department of the NavyUnited States Department of the Air Force (Contract AF19(604)-5200

Superbugs Versus Outsourced Cleaners: Employment Arrangements and the Spread of Health Care-Associated Infections

On any given day, about one in 25 hospital patients in the United States has a health care–associated infection (HAI) that the patient contracts as a direct result of his or her treatment. Fortunately, the spread of most HAIs can be halted through proper disinfection of surfaces and equipment. Consequently, cleaners—“environmental services” (EVS) in hospital parlance—must take on the important task of defending hospital patients (as well as staff and the broader community) from the spread of HAIs. Despite the importance of this task, hospitals frequently outsource this function, increasing the likelihood that these workers are under-rewarded, undertrained, and detached from the organization and the rest of the care team. As a result, the outsourcing of EVS workers could have the unintended consequence of increasing the incidence of HAIs. The authors demonstrate this relationship empirically, finding support for their theory by using a self-constructed data set that marries infection data to structural, organizational, and workforce features of California’s general acute care hospitals. The study thus advances the literature on nonstandard work arrangements—outsourcing in particular—while sounding a cautionary note to hospital administrators and health care policymakers

A Note on The Influence of Soil Parent Material on Northern Red OAK Specific Gravity

Soil parent material was found to affect the specific gravity of northern red oak wood (Quercus rubra L.). The unextracted specific gravity of wood grown on limestone soils was 0.597 and that of wood grown on sandstone soils was 0.581. Site quality within a soil type had no significant effect. The relationship was independent of both rate of growth and latewood percentage

3D-XY critical fluctuations of the thermal expansivity in detwinned YBa2Cu3O7-d single crystals near optimal doping

The strong coupling of superconductivity to the orthorhombic distortion in YBa2Cu3O7-d makes possible an analysis of the superconducting fluctuations without the necessity of subtracting any background. The present high-resolution capacitance dilatometry data unambiguously demonstrate the existence of critical, instead of Gaussian, fluctuations over a wide temperature region (+/- 10 K) around Tc. The values of the amplitude ratio A+/A-=0.9-1.1 and the leading scaling exponent |alpha|<0.018, determined via a least-squares fit of the data, are consistent with the 3D-XY universality class. Small deviations from pure 3D-XY behavior are discussed.Comment: 11 pages including three figure

Financial Information Mediation: A Case Study of Standards Integration for Electronic Bill Presentment and Payment Using the COIN Mediation Technology

Each player in the financial industry, each bank, stock exchange, government agency, or insurance company operates its own financial information system or systems. By its very nature, financial information, like the money that it represents, changes hands. Therefore the interoperation of financial information systems is the cornerstone of the financial services they support. E-services frameworks such as web services are an unprecedented opportunity for the flexible interoperation of financial systems. Naturally the critical economic role and the complexity of financial information led to the development of various standards. Yet standards alone are not the panacea: different groups of players use different standards or different interpretations of the same standard. We believe that the solution lies in the convergence of flexible E-services such as web-services and semantically rich meta-data as promised by the semantic Web; then a mediation architecture can be used for the documentation, identification, and resolution of semantic conflicts arising from the interoperation of heterogeneous financial services. In this paper we illustrate the nature of the problem in the Electronic Bill Presentment and Payment (EBPP) industry and the viability of the solution we propose. We describe and analyze the integration of services using four different formats: the IFX, OFX and SWIFT standards, and an example proprietary format. To accomplish this integration we use the COntext INterchange (COIN) framework. The COIN architecture leverages a model of sources and receivers’ contexts in reference to a rich domain model or ontology for the description and resolution of semantic heterogeneity.Singapore-MIT Alliance (SMA

Microwave Electronics

Contains research objectives and reports on three research projects.U.S. Navy (Office of Naval Research) under Contract Nonr-1841(49)U.S. Air Force under Air Force Contract AF19(604)-5200Lincoln Laboratory, Purchase Order DDL-B22

Three Methods of Determining Hardness of Increment Core Segments

Three methods were devised to measure the hardness of small wood samples: a sanding test, a diamond point indentation test, and a saw blade tooth deformity test. Based on step-wise multiple regression analysis with 19 and with five important independent variables, the sanding test was best, followed by the indentation test. The saw blade test gave poor results and was discarded. The order of important independent variables among the four plots analyzed individually showed a nearly perfect relationship with the sanding test, but no consistent order of the variables among plots for the indentation test. Again this indicated that the sanding test was best

The Case for Learned Index Structures

Indexes are models: a B-Tree-Index can be seen as a model to map a key to the position of a record within a sorted array, a Hash-Index as a model to map a key to a position of a record within an unsorted array, and a BitMap-Index as a model to indicate if a data record exists or not. In this exploratory research paper, we start from this premise and posit that all existing index structures can be replaced with other types of models, including deep-learning models, which we term learned indexes. The key idea is that a model can learn the sort order or structure of lookup keys and use this signal to effectively predict the position or existence of records. We theoretically analyze under which conditions learned indexes outperform traditional index structures and describe the main challenges in designing learned index structures. Our initial results show, that by using neural nets we are able to outperform cache-optimized B-Trees by up to 70% in speed while saving an order-of-magnitude in memory over several real-world data sets. More importantly though, we believe that the idea of replacing core components of a data management system through learned models has far reaching implications for future systems designs and that this work just provides a glimpse of what might be possible