3,035 research outputs found
Establishing a baseline for the study of maritime cultural heritage in the Gaza Strip
As a result of its geographic location, cultural diversity and historical trajectory, the Gaza strip is a key zone of scholarly enquiry and has a central role in the historical, social, political, economic, legislative and environmental discourses for the wider region. Existing historical knowledge of Gaza is dominated by combative narrative trends that emphasise the events of the 20th and 21st centuries and invoke archaeology extensively. In this context, cycles of material preservation and damage—often accompanying other forms of violence—have attracted the attention of academics and international media. Among the corollaries of this situation, is the destruction and marginalisation of vulnerable cultural heritage, particularly maritime cultural heritage, which is subjected to additional environmental, climatic, and anthropogenic pressures. As a means of countering the challenges on current field research in the region and to further assess the damage and threats faced by archaeological fabric, this paper combines data from coastal and archaeological research conducted in the Gaza Strip to create a benchmark for the study of its maritime archaeology. Additional information on the alteration of coastal landscape is deduced through the analysis of aerial photographs and satellite imagery. This study falls within the scope of the Maritime Endangered Archaeology in the Middle East and Africa Project (MarEA). MarEA aims to comprehensively document and assess vulnerable maritime archaeology (underwater, nearshore, coastal) and produce baseline information that can enhance existing infrastructure on archaeological monitoring and management.</p
Limitations in Predicting Radiation-Induced Pharmaceutical Instability during Long-Duration Spaceflight
As human spaceflight seeks to expand beyond low-Earth orbit, NASA and its
international partners face numerous challenges related to ensuring the safety
of their astronauts, including the need to provide a safe and effective
pharmacy for long-duration spaceflight. Historical missions have relied upon
frequent resupply of onboard pharmaceuticals; as a result, there has been
little study into the effects of long-term exposure of pharmaceuticals to the
space environment. Of particular concern are the long-term effects of space
radiation on drug stability, especially as missions venture away from the
protective proximity of the Earth. Here we highlight the risk of space
radiation to pharmaceuticals during exploration spaceflight, identifying the
limitations of current understanding. We further seek to identify ways in which
these limitations could be addressed through dedicated research efforts aimed
towards the rapid development of an effective pharmacy for future spaceflight
endeavors.Comment: in press, Nature Microgravit
Value of Mendelian Laws of Segregation in Families: Data Quality Control, Imputation, and Beyond
When analyzing family data, we dream of perfectly informative data, even whole-genome sequences (WGSs) for all family members. Reality intervenes, and we find that next-generation sequencing (NGS) data have errors and are often too expensive or impossible to collect on everyone. The Genetic Analysis Workshop 18 working groups on quality control and dropping WGSs through families using a genome-wide association framework focused on finding, correcting, and using errors within the available sequence and family data, developing methods to infer and analyze missing sequence data among relatives, and testing for linkage and association with simulated blood pressure. We found that single-nucleotide polymorphisms, NGS data, and imputed data are generally concordant but that errors are particularly likely at rare variants, for homozygous genotypes, within regions with repeated sequences or structural variants, and within sequence data imputed from unrelated individuals. Admixture complicated identification of cryptic relatedness, but information from Mendelian transmission improved error detection and provided an estimate of the de novo mutation rate. Computationally, fast rule-based imputation was accurate but could not cover as many loci or subjects as more computationally demanding probability-based methods. Incorporating population-level data into pedigree-based imputation methods improved results. Observed data outperformed imputed data in association testing, but imputed data were also useful. We discuss the strengths and weaknesses of existing methods and suggest possible future directions, such as improving communication between data collectors and data analysts, establishing thresholds for and improving imputation quality, and incorporating error into imputation and analytical models
Study of the island morphology at the early stages of Fe/Mo(110) MBE growth
We present theoretical study of morphology of Fe islands grown at Mo(110)
surface in sub-monolayer MBE mode. We utilize atomistic SOS model with bond
counting, and interactions of Fe adatom up to third nearest neighbors. We
performed KMC simulations for different values of adatom interactions and
varying temperatures. We have found that, while for the low temperature islands
are fat fractals, for the temperature 500K islands have faceted rhombic-like
shape. For the higher temperature, islands acquire a rounded shape. In order to
evaluated qualitatively morphological changes, we measured averaged aspect
ration of islands. We calculated dependence of the average aspect ratio on the
temperature, and on the strength of interactions of an adatom with neighbors.Comment: 6 pages, 6 figures. Proceedings of 11-th Symposium on Surface
Physics, Prague 200
Strichartz estimates on Schwarzschild black hole backgrounds
We study dispersive properties for the wave equation in the Schwarzschild
space-time. The first result we obtain is a local energy estimate. This is then
used, following the spirit of earlier work of Metcalfe-Tataru, in order to
establish global-in-time Strichartz estimates. A considerable part of the paper
is devoted to a precise analysis of solutions near the trapping region, namely
the photon sphere.Comment: 44 pages; typos fixed, minor modifications in several place
Eleven years of monitoring the Seyfert 1 Mrk 335 with Swift: Characterizing the X-ray and UV/optical variability
The narrow-line Seyfert 1 galaxy (NLS1) Mrk 335 has been continuously
monitored with Swift since May 2007 when it fell into a long-lasting, X-ray
low-flux interval. Results from the nearly 11 years of monitoring are presented
here. Structure functions are used to measure the UV-optical and X-ray power
spectra. The X-ray structure function measured between 10-100 days is
consistent with the flat, low-frequency part of the power spectrum measured
previously in Mrk 335. The UV-optical structure functions of Mrk 335 are
comparable with those of other Seyfert 1 galaxies and of Mrk 335 itself when it
was in a normal bright state. There is no indication that the current X-ray
low-flux state is attributed to changes in the accretion disc structure of Mrk
335. The characteristic timescales measured in the structure functions can be
attributed to thermal (for the UV) and dynamic (for the optical) timescales in
a standard accretion disc. The high-quality UVW2 (~1800 A in the source frame)
structure function appears to have two breaks and two different slopes between
10-160 days. Correlations between the X-ray and other bands are not highly
significant when considering the entire 11-year light curves, but more
significant behaviour is present when considering segments of the light curves.
A correlation between the X-ray and UVW2 in 2014 (Year-8) may be predominately
caused by an giant X-ray flare that was interpreted as jet-like emission. In
2008 (Year-2), possible lags between the UVW2 emission and other UV-optical
waveband may be consistent with reprocessing of X-ray or UV emission in the
accretion disc.Comment: Figure 8b has been corrected. 12 pages. Accepted for publication in
MNRA
The Strauss conjecture on asymptotically flat space-times
By assuming a certain localized energy estimate, we prove the existence
portion of the Strauss conjecture on asymptotically flat manifolds, possibly
exterior to a compact domain, when the spatial dimension is 3 or 4. In
particular, this result applies to the 3 and 4-dimensional Schwarzschild and
Kerr (with small angular momentum) black hole backgrounds, long range
asymptotically Euclidean spaces, and small time-dependent asymptotically flat
perturbations of Minkowski space-time. We also permit lower order perturbations
of the wave operator. The key estimates are a class of weighted Strichartz
estimates, which are used near infinity where the metrics can be viewed as
small perturbations of the Minkowski metric, and the assumed localized energy
estimate, which is used in the remaining compact set.Comment: Final version, to appear in SIAM Journal on Mathematical Analysis. 17
page
Identifying and Defining the Structures That Guide the Implementation of Participant Direction Programs and Support Program Participants: A Document Analysis
This is the author's accepted manuscript. The published version is available at http://dx.doi.org/10.1177/1044207313514112Participant direction (PD) programs offer the individual with a disability or his or her surrogate decision maker varying degrees of choice and control over the individual’s supports and services. We conducted a document analysis using grounded theory methods to identify the design elements of participant direction programs in long-term care. We analyzed 53 documents across multiple disabilities and funding sources. We identified and defined two major components of participant direction programs: policy and aid and assistance. The component of policy was represented by three structures that guide implementation of participant direction programs: (a) option to participant-direct, (b) participation stipulations, and (c) provider qualifications. The component of aid and assistance was represented by 11 structures that support program participants: (a) financial management services, (b) employer of record, (c) emergency back-up, (d) worker registry, (e) advice/counseling, (f) managerial assistance, (g) information dissemination products, (h) service quality monitoring, (i) service coordination, (j) participant training, and (k) provider training. Each structure was represented by one or more continua depicting the range of choice and control participants may have over the structure. The findings of this study have implications for improving the standardization of research on participant direction programs and the development of long-term care policy
Identifying and defining the activities of participant direction programs: A document analysis
This is the author's accepted manuscript. The published version is available at http://dx.doi.org/10.1177/1044207313502538We analyzed the design of various U.S. programs of participant direction offering participants (individual with a disability or his or her surrogate decision-maker) some level of choice and control over the individual’s long-term care supports and services. We used grounded theory methods to conduct a document analysis of 53 documents published from 2004 through 2008 representing multiple disabilities and program funding sources. In our analysis, we identified three major components (planning, budgeting, and employing) over which participants had the opportunity to exercise choice and control and the activities associated with each. Activities were represented by one or more continua illustrating the range of participant choice and control over the indicator. The component of planning consisted of the activity of care plan development. The budgeting component included the activities of (a) development, (b) individualization, and (c) authority. The employing component included the activities of (a) identifying/selecting providers, (b) hiring/employing providers, (c) scheduling providers, (d) training providers, (e) managing/directing/supervising providers, (f) disciplining/dismissing providers, (g) keeping records, (h) managing payroll, (i) locating emergency back-up, and (j) monitoring service quality. The findings of this study have implications for improving policy, practice, and research in the field of long-term care
Effects of communication and utility-based decision making in a simple model of evacuation
We present a simple cellular automaton based model of decision making during
evacuation. Evacuees have to choose between two different exit routes,
resulting in a strategic decision making problem. Agents take their decisions
based on utility functions, these can be revised as the evacuation proceeds,
leading to complex interaction between individuals and to jamming transitions.
The model also includes the possibility to communicate and exchange information
with distant agents, information received may affect the decision of agents. We
show that under a wider range of evacuation scenarios performance of the model
system as a whole is optimal at an intermediate fraction of evacuees with
access to communication.Comment: 9 pages, 9 figure
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