Can the Mortonson-Pissarides matching model match the business cycle facts?

We examine whether the Mortensen-Pissarides matching model can account for the business cycle facts on employment, job creation, and job destruction. A novel feature of our analysis is its emphasis on the reduced-form implications of the matching model. Our main finding is that the model can account for the business cycle facts, but only if the average duration of a nonemployment spell is relatively high—about nine months or longer.Business cycles

Supersonic propulsion simulation by incorporating component models in the large perturbation inlet (LAPIN) computer code

An approach to simulating the internal flows of supersonic propulsion systems is presented. The approach is based on a fairly simple modification of the Large Perturbation Inlet (LAPIN) computer code. LAPIN uses a quasi-one dimensional, inviscid, unsteady formulation of the continuity, momentum, and energy equations. The equations are solved using a shock capturing, finite difference algorithm. The original code, developed for simulating supersonic inlets, includes engineering models of unstart/restart, bleed, bypass, and variable duct geometry, by means of source terms in the equations. The source terms also provide a mechanism for incorporating, with the inlet, propulsion system components such as compressor stages, combustors, and turbine stages. This requires each component to be distributed axially over a number of grid points. Because of the distributed nature of such components, this representation should be more accurate than a lumped parameter model. Components can be modeled by performance map(s), which in turn are used to compute the source terms. The general approach is described. Then, simulation of a compressor/fan stage is discussed to show the approach in detail

Initial operating capability for the hypercluster parallel-processing test bed

The NASA Lewis Research Center is investigating the benefits of parallel processing to applications in computational fluid and structural mechanics. To aid this investigation, NASA Lewis is developing the Hypercluster, a multi-architecture, parallel-processing test bed. The initial operating capability (IOC) being developed for the Hypercluster is described. The IOC will provide a user with a programming/operating environment that is interactive, responsive, and easy to use. The IOC effort includes the development of the Hypercluster Operating System (HYCLOPS). HYCLOPS runs in conjunction with a vendor-supplied disk operating system on a Front-End Processor (FEP) to provide interactive, run-time operations such as program loading, execution, memory editing, and data retrieval. Run-time libraries, that augment the FEP FORTRAN libraries, are being developed to support parallel and vector processing on the Hypercluster. Special utilities are being provided to enable passage of information about application programs and their mapping to the operating system. Communications between the FEP and the Hypercluster are being handled by dedicated processors, each running a Message-Passing Kernel, (MPK). A shared-memory interface allows rapid data exchange between HYCLOPS and the communications processors. Input/output handlers are built into the HYCLOPS-MPK interface, eliminating the need for the user to supply separate I/O support programs on the FEP

A message passing kernel for the hypercluster parallel processing test bed

A Message-Passing Kernel (MPK) for the Hypercluster parallel-processing test bed is described. The Hypercluster is being developed at the NASA Lewis Research Center to support investigations of parallel algorithms and architectures for computational fluid and structural mechanics applications. The Hypercluster resembles the hypercube architecture except that each node consists of multiple processors communicating through shared memory. The MPK efficiently routes information through the Hypercluster, using a message-passing protocol when necessary and faster shared-memory communication whenever possible. The MPK also interfaces all of the processors with the Hypercluster operating system (HYCLOPS), which runs on a Front-End Processor (FEP). This approach distributes many of the I/O tasks to the Hypercluster processors and eliminates the need for a separate I/O support program on the FEP

Microtubule disassembly delays the G2–M transition in vertebrates

AbstractWhen cell cultures in growth are treated with drugs that cause microtubules to disassemble, the mitotic index (MI) progressively increases as the cells accumulate in a C-mitosis. For many cell types, however, including rat kangaroo kidney PtK1 cells, the MI does not increase during the first several hours of treatment [1–3] (Figure 1). This ‘lag’ implies either that cells are entering mitosis but rapidly escaping the block, or that they are delayed from entering division. To differentiate between these possibilities, we fixed PtK1 cultures 0, 90 and 270 minutes after treatment with nocodazole, colcemid, lumi-colcemid, taxol or cytochalasin D. After 90 minutes, we found that the numbers of prophase cells in cultures treated with nocodazole or colcemid were reduced by ∼80% relative to cultures treated with lumi-colcemid, cytochalasin D or taxol. Thus, destroying microtubules delays late G2 cells from entering prophase and, as the MI does not increase during this time, existing prophase cells do not enter prometaphase. When mid-prophase cells were treated with nocodazole, the majority (70%) decondensed their chromosomes and returned to G2 before re-entering and completing prophase 3–10 hours later. Thus, a pathway exists in vertebrates that delays the G2–M transition when microtubules are disassembled during the terminal stages of G2. As this pathway induces mid-prophase cells to transiently decondense their chromosomes, it is likely that it downregulates the cyclin A–cyclin-dependent kinase 2 (CDK2) complex, which is required in vertebrates for the early stages of prophase [4]

Professionalism And Self-Regulation

Dr. Perle's article on chiropractic professionalism and standards.http://www.dynamicchiropractic.com/mpacms/dc/article.php?id=5225

Impacts of recreation on biodiversity in wilderness

We discuss seven recreational impacts on biodiversity in wilderness areas. These include: 1) construction of trails, 2) trampling of vegetation and soils on trails and campsites, 3) collection and burning of wood in campfires, 4) water pollution associated with camping activities, 5) unintentional harassment of animals, 6) hunting, fishing, and associated management programs, and 7) grazing by processes and functions of ecosystems. The activities which have caused the greatest impact on diversity at a regional scale are fishing, hunting and associated management practices. None of these perturbations, however, have been studied in insufficient detail to assess their long-term impact

Incorporating UTAUT Predictors for Understanding Home Care Patients’ and Clinician’s Acceptance of Healthcare Telemedicine Equipment

Telemedicine programs within health care are experiencing significant growth as healthcare organizations seek to reduce expenditures and improve efficiency. The high costs of treating chronic diseases, compounded by an aging population, has given focus to creating technology-enabled alternatives to support, enhance, or expand patient services. As investments in telemedicine products and services grow at a rapid pace, user technology acceptance has become a key issue in successful implementation. Drawing from the Unified Theory of Acceptance in Technology (UTAUT), this study investigated the predictors of behavioral intention to use Telehealth equipment by patients, clinicians, and agency personnel at Henry Ford e-Home Health Care. Survey data were provided by 126 participants recruited from an eligible population who were either currently using the Telehealth equipment or were familiar with it. Structural equation modeling was used to study the overall fit of the UTAUT model in predicting behavioral intention. Participant type, self-efficacy, anxiety and attitude were tested as moderators. Implications for increasing adoption of Telehealth technology are discussed

Characteristics of Texas' 1964 National Political Convention Delegations

"It is the purpose of this study is to examine these characteristics of the delegates from Texas to the 1964 Democratic and Republican national nominating conventions, as well as to compare and contrast their characteristics. It is a basic assumption of this study that the characteristics of national convention delegates are important in the determination of the character of the convention as an institution."-- leaf 2

Atomistic simulations of adiabatic coherent electron transport in triple donor systems

A solid-state analogue of Stimulated Raman Adiabatic Passage can be implemented in a triple well solid-state system to coherently transport an electron across the wells with exponentially suppressed occupation in the central well at any point of time. Termed coherent tunneling adiabatic passage (CTAP), this method provides a robust way to transfer quantum information encoded in the electronic spin across a chain of quantum dots or donors. Using large scale atomistic tight-binding simulations involving over 3.5 million atoms, we verify the existence of a CTAP pathway in a realistic solid-state system: gated triple donors in silicon. Realistic gate profiles from commercial tools were combined with tight-binding methods to simulate gate control of the donor to donor tunnel barriers in the presence of cross-talk. As CTAP is an adiabatic protocol, it can be analyzed by solving the time independent problem at various stages of the pulse - justifying the use of time-independent tight-binding methods to this problem. Our results show that a three donor CTAP transfer, with inter-donor spacing of 15 nm can occur on timescales greater than 23 ps, well within experimentally accessible regimes. The method not only provides a tool to guide future CTAP experiments, but also illuminates the possibility of system engineering to enhance control and transfer times.Comment: 8 pages, 5 figure