1,548 research outputs found
Healthcare Information Systems (HCIS) Curriculum
There is a reawakening of enthusiasm for Healthcare topics at AMCIS, witnessed, too, by the formation of a Healthcare SIG. At the same time, numerous AMCIS attendees lamented the challenges of developing an effective and contemporary undergraduate and graduate curriculum for Healthcare MIS. The field is growing rapidly, and includes diverse healthoriented topics and sub-specialties like bioinformatics, nursing informatics, home healthcare technologies, telemedicine, privacy and security, e-Health, and a wide range of patient-, clinical- and managerial-decision support systems. For this panel we have assembled a well-seasoned group of speakers and educators to advance our collective ability to teach âstate of the artâ courses in this critically important area
RNA force field with accuracy comparable to state-of-the-art protein force fields
Molecular dynamics (MD) simulation has become a powerful tool for characterizing at an atomic level of detail the conformational changes undergone by proteins. The application of such simulations to RNA structures, however, has proven more challenging, due in large part to the fact that the physical models (âforce fieldsâ) available for MD simulations of RNA molecules are substantially less accurate in many respects than those currently available for proteins. Here, we introduce an extensive revision of a widely used RNA force field in which the parameters have been modified, based on quantum mechanical calculations and existing experimental information, to more accurately reflect the fundamental forces that stabilize RNA structures. We evaluate these revised parameters through long-timescale MD simulations of a set of RNA molecules that covers a wide range of structural complexity, including single-stranded RNAs, RNA duplexes, RNA hairpins, and riboswitches. The structural and thermodynamic properties measured in these simulations exhibited dramatically improved agreement with experimentally determined values. Based on the comparisons we performed, this RNA force field appears to achieve a level of accuracy comparable to that of state-of-the-art protein force fields, thus significantly advancing the utility of MD simulation as a tool for elucidating the structural dynamics and function of RNA molecules and RNA-containing biological assemblies
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Reactive nitrogen in Asian continental outflow over the western Pacific: Results from the NASA Transport and Chemical Evolution over the Pacific (TRACE-P) airborne mission
We present here results for reactive nitrogen species measured aboard the NASA DC-8 aircraft during the Transport and Chemical Evolution over the Pacific (TRACE-P) mission. The large-scale distributions total reactive nitrogen (NOy,sum = NO + NO2 + HNO3 + PAN + C1âC5alkyl nitrates) and O3 and CO were better defined in the boundary layer with significant degradation of the relationships as altitude increased. Typically, NOy,sum was enhanced over background levels of âŒ260 pptv by 20-to-30-fold. The ratio C2H2/CO had values of 1â4 at altitudes up to 10 km and as far eastward as 150°E, implying significant vertical mixing of air parcels followed by rapid advection across the Pacific. Analysis air parcels originating from five principal Asian source regions showed that HNO3 and PAN dominated NOy,sum. Correlations of NOy,sum with C2Cl4 (urban tracer) were not well defined in any of the source regions, and they were only slightly better with CH3Cl (biomass tracer). Air parcels over the western Pacific contained a complex mixture of emission sources that are not easily resolvable as shown by analysis of the Shanghai mega-city plume. It contained an intricate mixture of pollution emissions and exhibited the highest mixing ratios of NOy,sum species observed during TRACE-P. Comparison of tropospheric chemistry between the earlier PEM-West B mission and the recent TRACE-P data showed that in the boundary layer significant increases in the mixing ratios of NOy,sum species have occurred, but the middle and upper troposphere seems to have been affected minimally by increasing emissions on the Asian continent over the last 7 years
Diversification of DNA-Binding Specificity by Permissive and Specificity-Switching Mutations in the ParB/Noc Protein Family
Specific interactions between proteins and DNA are essential to many biological processes. Yet, it remains unclear how the diversification in DNA-binding specificity was brought about, and the mutational paths that led to changes in specificity are unknown. Using a pair of evolutionarily related DNA-binding proteins, each with a different DNA preference (ParB [Partitioning Protein B] and Noc [Nucleoid Occlusion Factor], which both play roles in bacterial chromosome maintenance), we show that specificity is encoded by a set of four residues at the protein-DNA interface. Combining X-ray crystallography and deep mutational scanning of the interface, we suggest that permissive mutations must be introduced before specificity-switching mutations to reprogram specificity and that mutational paths to new specificity do not necessarily involve dual-specificity intermediates. Overall, our results provide insight into the possible evolutionary history of ParB and Noc and, in a broader context, might be useful for understanding the evolution of other classes of DNA-binding proteins
Designing a Mobile Crowdsourcing System for Campus Safety
Safety on college campuses remains a dire issue. Current reporting methods are still cumbersome and include no enhancing social aspect. Given the unique opportunity that universities are required to publish their safety report logs, we conducted a preliminary data analysis of a university's safety report log. The analysis allowed us to detect relevant trends in reporting behavior, specifically pertaining to where, when, and how soon the community would report safety incidents. Motivated by these findings and by literature promoting interactive reporting systems, we designed a novel mobile app which aims to enable the spread of crowdsourced public safety information. This app allows for immediate mass sharing of self-reported safety incidents, as well as the opportunity for witness reporting. Feedback from a paper prototype interview study indicated that these qualities would facilitate increased interactivity among its user community, and ultimately promote awareness of campus safety.ye
Using Bayes to get the most out of non-significant results
No scientific conclusion follows automatically from a statistically non-significant result, yet people routinely use non-significant results to guide conclusions about the status of theories (or the effectiveness of practices). To know whether a non-significant result counts against a theory, or if it just indicates data insensitivity, researchers must use one of: power, intervals (such as confidence or credibility intervals), or else an indicator of the relative evidence for one theory over another, such as a Bayes factor. I argue Bayes factors allow theory to be linked to data in a way that overcomes the weaknesses of the other approaches. Specifically, Bayes factors use the data themselves to determine their sensitivity in distinguishing theories (unlike power), and they make use of those aspects of a theoryâs predictions that are often easiest to specify (unlike power and intervals, which require specifying the minimal interesting value in order to address theory). Bayes factors provide a coherent approach to determining whether non-significant results support a null hypothesis over a theory, or whether the data are just insensitive. They allow accepting and rejecting the null hypothesis to be put on an equal footing. Concrete examples are provided to indicate the range of application of a simple online Bayes calculator, which reveal both the strengths and weaknesses of Bayes factors
Volatile evolution and atmospheres of Trans-Neptunian Objects
At 30-50 K, the temperatures typical for surfaces in the Kuiper Belt (e.g.
Stern & Trafton 2008), only seven species have sublimation pressures higher
than 1 nbar (Fray & Schmitt 2009): Ne, N, CO, Ar, O, CH, and Kr. Of
these, N, CO, and CH have been detected or inferred on the surfaces of
Trans-Neptunian Objects (TNOs). The presence of tenuous atmospheres above these
volatile ices depends on the sublimation pressures, which are very sensitive to
the composition, temperatures, and mixing states of the volatile ices.
Therefore, the retention of volatiles on a TNO is related to its formation
environment and thermal history. The surface volatiles may be transported via
seasonally varying atmospheres and their condensation might be responsible for
the high surface albedos of some of these bodies. The most sensitive searches
for tenuous atmospheres are made by the method of stellar occultation, which
have been vital for the study of the atmospheres of Triton and Pluto, and has
to-date placed upper limits on the atmospheres of 11 other bodies. The recent
release of the Gaia astrometric catalog has led to a "golden age" in the
ability to predict TNO occultations in order to increase the observational data
base
Isotopic composition of fragments in multifragmentation of very large nuclear systems: effects of the chemical equilibrium
Studies on the isospin of fragments resulting from the disassembly of highly
excited large thermal-like nuclear emitting sources, formed in the ^{197}Au +
^{197}Au reaction at 35 MeV/nucleon beam energy, are presented. Two different
decay systems (the quasiprojectile formed in midperipheral reactions and the
unique source coming from the incomplete fusion of projectile and target in the
most central collisions) were considered; these emitting sources have the same
initial N/Z ratio and excitation energy (E^* ~= 5--6 MeV/nucleon), but
different size. Their charge yields and isotopic content of the fragments show
different distributions. It is observed that the neutron content of
intermediate mass fragments increases with the size of the source. These
evidences are consistent with chemical equilibrium reached in the systems. This
fact is confirmed by the analysis with the statistical multifragmentation
model.Comment: 9 pages, 4 ps figure
Multi-band ESCL transmission supported by bismuth-doped and Raman fiber amplification
Ultra-wideband transmission utilizes bandwidths beyond the standard C-band to enable significant network capacity upgrades. Upgrading the standard C-band to a C+L-band transmission scenario is already feasible, and exploratory transmission is being performed in the S-, E-, and O-bands to investigate quality of transmission (QoT) impairments in these spectral regions. In this paper, experimental transmission through a SCL- and partial E-band spectral region is performed, with use of a hybrid amplifier that exploits discrete Raman amplification for the SCL-bands, and a bismuth-doped fiber amplifier (BDFA) for the E-band. Through this transmission bandwidth, we demonstrate that 36 Tbit/s transmission is possible, with 150 coherent channels over 70 km of standard, single-mode fiber. This result is compared to a wideband physical layer model that considers a realistic full spectral load transmission scenario, where the E-band is occupied by 74 channels, providing a total of 221 channels. This comparison demonstrates that, for both scenarios in this experiment, the greatest impairment is present within the S-band, and the addition of the E-band to a SCL-band scenario has a negligible impact upon the QoT within the C- and L-bands
Just in case it rains:building a hydrophobic biofilm the <i>Bacillus subtilis</i> way
Over the millennia, diverse species of bacteria have evolved multiple independent mechanisms to structure sessile biofilm communities that confer protection and stability to the inhabitants. The Gram-positive soil bacterium Bacillus subtilis biofilm presents as an architecturally complex, highly hydrophobic community that resists wetting by water, solvents, and biocides. This remarkable property is conferred by a small secreted protein called BslA, which self-assembles into an organized lattice at an interface. In the biofilm, production of BslA is tightly regulated and the resultant protein is secreted into the extracellular environment where it forms a very effective communal barrier allowing the resident B. subtilis cells to shelter under the protection of a protein raincoat
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