2,096 research outputs found
Precision shooting: Sampling long transition pathways
The kinetics of collective rearrangements in solution, such as protein
folding and nanocrystal phase transitions, often involve free energy barriers
that are both long and rough. Applying methods of transition path sampling to
harvest simulated trajectories that exemplify such processes is typically made
difficult by a very low acceptance rate for newly generated trajectories. We
address this problem by introducing a new generation algorithm based on the
linear short-time behavior of small disturbances in phase space. Using this
``precision shooting'' technique, arbitrarily small disturbances can be
propagated in time, and any desired acceptance ratio of shooting moves can be
obtained. We demonstrate the method for a simple but computationally
problematic isomerization process in a dense liquid of soft spheres. We also
discuss its applicability to barrier crossing events involving metastable
intermediate states.Comment: 9 pages, 12 figures, submitted to J. Chem. Phy
Note – Private Eyes Watching You: Google Street View and the Right to an Inviolate Personality
Google’s rollout of its Street View service in North America in 2007 provoked little concern about the privacy implications of private homes and individuals being easily viewed by potentially millions of persons. In contrast, Street View’s reception in Europe, particularly in Germany, has been marked by episodes of both public outrage and government concern. These divergent reactions can be explained in part by differing conceptions of the right to privacy—with European concepts of privacy based generally on the notion that an individual’s “dignity” should be protected—and the differing levels of protection afforded by those conceptions to aspects of a person’s identity. This Note compares the legal protections afforded to individuals’ privacy in the U.S. and in Germany. In particular, this Note looks at the concept of the right to an “inviolate personality” that pervades privacy protection in Germany. This Note argues that such a right can be found in U.S. privacy jurisprudence, and that this right protects persons against the actions of private as well as government agents. Lastly, this Note argues that privacy rights must be defined broadly in an era when Street View is expanding to cover not just public streets and alleys, but also the interiors of museums and even places of business
Utilization rates of hip arthroplasty in OECD countries
SummaryBackgroundHip arthroplasty and revision surgery is growing exponentially in OECD countries, but rates vary between countries.MethodsWe extracted economic data and utilization rates data about hip arthroplasty done in OECD countries between 1990 and 2011. Absolute number of implantations and compound annual growth rates were computed per 100,000 population and for patients aged 65 years old and over and for patients aged 64 years and younger.ResultsIn the majority of OECD countries, there has been a significant increase in the utilization of total hip arthroplasty in the last 10 years, but rates vary to a great extent: In the United States, Switzerland, and Germany the utilization rate exceeds 200/100,000 population whereas in Spain and Mexico rates are 102 and 8, respectively. There is a strong correlation between gross domestic product (GDP) and health care expenditures per capita with utilization rate. Utilization rates in all age groups have continued to rise up to present day. A seven fold higher growth rate was seen in patients aged 64 years and younger as compared to older patients.ConclusionWe observed a 38-fold variation in the utilization of hip arthroplasty among OECD countries, correlating with GDP and health care expenditures. Over recent years, there has been an increase in the utilization rate in most countries. This was particularly evident in the younger patients. Due to increasing life expectancy and the disproportionally high use of arthroplasty in younger patients we expect an exponential increase of revision rate in the future
The relationship between violence in Northern Mexico and potentially avoidable hospitalizations in the USA–Mexico border region
BACKGROUND: Substantial proportions of US residents in the USA-Mexico border region cross into Mexico for health care; increases in violence in northern Mexico may have affected this access. We quantified associations between violence in Mexico and decreases in access to care for border county residents. We also examined associations between border county residence and access.
METHODS: We used hospital inpatient data for Arizona, California and Texas (2005-10) to estimate associations between homicide rates and the probability of hospitalization for ambulatory care sensitive (ACS) conditions. Hospitalizations for ACS conditions were compared with homicide rates in Mexican municipalities matched by patient residence.
RESULTS: A 1 SD increase in the homicide rate of the nearest Mexican municipality was associated with a 2.2 percentage point increase in the probability of being hospitalized for an ACS condition for border county patients. Residence in a border county was associated with a 1.3 percentage point decrease in the probability of being hospitalized for an ACS condition.
CONCLUSIONS: Increased homicide rates in Mexico were associated with increased hospitalizations for ACS conditions in the USA, although residence in a border county was associated with decreased probability of being hospitalized for an ACS condition. Expanding access in the border region may mitigate these effects by providing alternative sources of care
Lab::Measurement - A portable and extensible framework for controlling lab equipment and conducting measurements
Lab::Measurement is a framework for test and measurement automatization using
Perl 5. While primarily developed with applications in mesoscopic physics in
mind, it is widely adaptable. Internally, a layer model is implemented.
Communication protocols such as IEEE 488, USB Test & Measurement, or, e.g.,
VXI-11 are addressed by the connection layer. The wide range of supported
connection backends enables unique cross-platform portability. At the
instrument layer, objects correspond to equipment connected to the measurement
PC (e.g., voltage sources, magnet power supplies, multimeters, etc.). The
high-level sweep layer automates the creation of measurement loops, with
simultaneous plotting and data logging. An extensive unit testing framework is
used to verify functionality even without connected equipment. Lab::Measurement
is distributed as free and open source software.Comment: Published version (open access, CC BY 4.0). 7 pages; refers to
Lab::Measurement 3.660, see https://www.labmeasurement.de
Evolving friendships and shifting ethical dilemmas: fieldworkers' experiences in a short term community based study in Kenya
Fieldworkers (FWs) are community members employed by research teams to support access to participants, address language barriers, and advise on culturally appropriate research conduct. The critical role that FWs play in studies, and the range of practical and ethical dilemmas associated with their involvement, is increasingly recognised. In this paper, we draw on qualitative observation and interview data collected alongside a six month basic science study which involved a team of FWs regularly visiting 47 participating households in their homes. The qualitative study documented how relationships between field workers and research participants were initiated, developed and evolved over the course of the study, the shifting dilemmas FWs faced and how they handled them. Even in this one case study, we see how the complex and evolving relationships between fieldworkers and study participants had important implications for consent processes, access to benefits and mutual understanding and trust. While the precise issues that FWs face are likely to depend on the type of research and the context in which that research is being conducted, we argue that appropriate support for field workers is a key requirement to strengthen ethical research practice and for the long term sustainability of research programmes
Galileo dust data from the jovian system: 2000 to 2003
The Galileo spacecraft was orbiting Jupiter between Dec 1995 and Sep 2003.
The Galileo dust detector monitored the jovian dust environment between about 2
and 370 R_J (jovian radius R_J = 71492 km). We present data from the Galileo
dust instrument for the period January 2000 to September 2003. We report on the
data of 5389 particles measured between 2000 and the end of the mission in
2003. The majority of the 21250 particles for which the full set of measured
impact parameters (impact time, impact direction, charge rise times, charge
amplitudes, etc.) was transmitted to Earth were tiny grains (about 10 nm in
radius), most of them originating from Jupiter's innermost Galilean moon Io.
Their impact rates frequently exceeded 10 min^-1. Surprisingly large impact
rates up to 100 min^-1 occurred in Aug/Sep 2000 when Galileo was at about 280
R_J from Jupiter. This peak in dust emission appears to coincide with strong
changes in the release of neutral gas from the Io torus. Strong variability in
the Io dust flux was measured on timescales of days to weeks, indicating large
variations in the dust release from Io or the Io torus or both on such short
timescales. Galileo has detected a large number of bigger micron-sized
particles mostly in the region between the Galilean moons. A surprisingly large
number of such bigger grains was measured in March 2003 within a 4-day interval
when Galileo was outside Jupiter's magnetosphere at approximately 350 R_J
jovicentric distance. Two passages of Jupiter's gossamer rings in 2002 and 2003
provided the first actual comparison of in-situ dust data from a planetary ring
with the results inferred from inverting optical images.Comment: 59 pages, 13 figures, 6 tables, submitted to Planetary and Space
Scienc
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