5,545 research outputs found
Immittance Spectroscopy of Smart Components and Novel Devices
AC small-signal immittance spectroscopy is employed as a viable tool to demonstrate electrical characterization, performance improvement, and quality assurance issues of smart materials-based components and novel devices. The variation in the ac response, complemented via dc measurements within a range of tolerating temperature, delineates competing phenomena occurring in the microstructures of these engineering material systems. The results are presented in a generic manner with possible explanations on the mechanisms for two selected Debye-like (nearly ideal) and non-Debye (non-ideal) low-capacitance resistors. This spectroscopic approach allows systematic development of a representative equivalent circuit, considered to be the characteristic of the devices and components, for specific applications
Submicron Systems Architecture Project : Semiannual Technical Report
The Mosaic C is an experimental fine-grain multicomputer
based on single-chip nodes. The Mosaic C chip includes 64KB of fast dynamic RAM,
processor, packet interface, ROM for bootstrap and self-test, and a two-dimensional selftimed
router. The chip architecture provides low-overhead and low-latency handling of
message packets, and high memory and network bandwidth. Sixty-four Mosaic chips are
packaged by tape-automated bonding (TAB) in an 8 x 8 array on circuit boards that can, in
turn, be arrayed in two dimensions to build arbitrarily large machines. These 8 x 8 boards are
now in prototype production under a subcontract with Hewlett-Packard. We are planning
to construct a 16K-node Mosaic C system from 256 of these boards. The suite of Mosaic
C hardware also includes host-interface boards and high-speed communication cables. The
hardware developments and activities of the past eight months are described in section 2.1.
The programming system that we are developing for the Mosaic C is based on the
same message-passing, reactive-process, computational model that we have used with earlier
multicomputers, but the model is implemented for the Mosaic in a way that supports finegrain
concurrency. A process executes only in response to receiving a message, and may in
execution send messages, create new processes, and modify its persistent variables before
it either exits or becomes dormant in preparation for receiving another message. These
computations are expressed in an object-oriented programming notation, a derivative of
C++ called C+-. The computational model and the C+- programming notation are
described in section 2.2. The Mosaic C runtime system, which is written in C+-, provides
automatic process placement and highly distributed management of system resources. The
Mosaic C runtime system is described in section 2.3
who is missed and why?
Background Public health monitoring depends on valid health and disability
estimates in the population 65+ years. This is hampered by high non-
participation rates in this age group. There is limited insight into size and
direction of potential baseline selection bias. Methods We analyzed baseline
non-participation in a register-based random sample of 1481 inner-city
residents 65+ years, invited to a health examination survey according to
demographics available for the entire sample, self-report information as
available and reasons for non-participation. One year after recruitment, non-
responders were revisited to assess their reasons. Results Five groups defined
by participation status were differentiated: participants (N = 299), persons
who had died or moved (N = 173), those who declined participation, but
answered a short questionnaire (N = 384), those who declined participation and
the short questionnaire (N = 324), and non-responders (N = 301). The results
confirm substantial baseline selection bias with significant
underrepresentation of persons 85+ years, persons in residential care or from
disadvantaged neighborhoods, with lower education, foreign citizenship, or
lower health-related quality of life. Finally, reasons for non-participation
could be identified for 78 % of all non-participants, including 183 non-
responders. Conclusion A diversity in health problems and barriers to
participation exists among non-participants. Innovative study designs are
needed for public health monitoring in aging populations
Microbiology: Mind the gaps in cellular evolution
Eukaryotic cells, with complex features such as membrane-bound nuclei, evolved from prokaryotic cells that lack these components. A newly identified prokaryotic group reveals intermediate steps in eukaryotic-cell evolution
Student, faculty, and staff approval of university smoke/tobacco-free policies: an analysis of campus newspaper articles
Objective: To provide a nontraditional source of data to university policymakers regarding student, faculty, and staff approval of university smoke/tobacco-free policies, as published through campus newspaper articles. Methods: From January to April 2016, a total of 2523 articles were retrieved concerning campus smoking/tobacco at 4-year, public universities. Of these, 54 articles met the inclusion factors, which described 30 surveys about campus approval of tobacco-free policies and 24 surveys about smoke-free policies. Results: In all, the surveys included more than 130 000 respondents. With the exception of 4 surveys, all reported that the most of the respondents approved a tobacco/smoke-free campus policy. Conclusions: Although the study had several limitations, the findings provide a synthesis from a nontraditional data source that is consistent with findings from the peer-reviewed literature, in which most of the students, faculty, and staff on university campuses approve of smoke/tobacco-free campus policies
SuperCDMS Cold Hardware Design
We discuss the current design of the cold hardware and cold electronics to be used in the upcoming SuperCDMS Soudan deployment. Engineering challenges associated with such concerns as thermal isolation, microphonics, radiopurity, and power dissipation are discussed, along with identifying the design changes necessary for SuperCDMS SNOLAB. The Cryogenic Dark Matter Search (CDMS) employs ultrapure 1-inch thick, 3-inch diameter germanium crystals operating below 50Â mK in a dilution cryostat. These detectors give an ionization and phonon signal, which gives us rejection capabilities regarding background events versus dark matter signals.United States. Dept. of Energy (Grant DEAC02-76SF00515)United States. Dept. of Energy (Contract DC-AC02-07CH11359)National Science Foundation (U.S.) (Awards 0705052, 0902182, 1004714 and 0802575
Electrochemotherapy with Bleomycin Enhances Radiosensitivity of Uveal Melanomas: First In Vitro Results in 3D Cultures of Primary Uveal Melanoma Cell Lines
Electrochemotherapy (ECT) is emerging as a complementary treatment modality for local
tumor control in various cancer entities. Irradiation is an established therapeutic option for oncologic
patients, which is commonly combined with chemotherapy due to its insufficient targeting ability.
The efficiency of radiotherapy for tumors can be enhanced with different radiosensitizers. ECT can
potentiate the radiosensitizing effect of chemotherapeutic agents such as bleomycin. The present
study aims to evaluate the radiosensitizing effect of concomitant ECT with bleomycin on 3D tumor
spheroids with primary and radioresistant uveal melanoma cell lines (UPMD2, UPMM3, UM92.1,
Mel270) and irradiation. The changes in the spheroid growth and the cell viability as well the
cytotoxic long-term effect of the combination treatment were evaluated with various combinations
of electroporation settings and bleomycin concentrations as well as radiotherapy doses. A broad
range of radiosensitivity was documented among the spheroids from different uveal melanoma cell
lines. The primary cell lines showed a higher radiosensitivity and required lower irradiation and
bleomycin doses. The maximal tumor control with a reduction of cell survival <10% was achieved
with a 5 Gy irradiation only in the primary uveal melanoma cell lines and in combination with all
tested ECT settings, whereas the same result could be obtained in UM92.1 spheroids only after ECT
with 20 Gy irradiation. Based on the spheroid growth and the measurement of the cross-sectional
area, the Mel270 spheroids, originating from a previously irradiated recurrent uveal melanoma,
required higher doses of bleomycin and ECT settings after irradiation with 5 Gy in order to achieve a
significant growth reduction. No significant difference could be demonstrated for the reduction of cell
viability in the combination therapy with 20 Gy and 1000 V/cm between 1 and 2.5 µg/mL bleomycin even in Mel270 spheroids, underlying the importance of a drug delivery system to potentiate the
radiosensitizing effect of agents in lower doses. ECT should be further assessed for its applicability
in clinical settings as a therapeutic radiosensitizing option for radioresistant tumors and a sufficient
local tumor control with lower chemotherapy and irradiation doses
Modeling Elasticity in Crystal Growth
A new model of crystal growth is presented that describes the phenomena on
atomic length and diffusive time scales. The former incorporates elastic and
plastic deformation in a natural manner, and the latter enables access to times
scales much larger than conventional atomic methods. The model is shown to be
consistent with the predictions of Read and Shockley for grain boundary energy,
and Matthews and Blakeslee for misfit dislocations in epitaxial growth.Comment: 4 pages, 10 figure
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