1,392 research outputs found
Privacy Preserving Internet Browsers: Forensic Analysis of Browzar
With the advance of technology, Criminal Justice agencies are being
confronted with an increased need to investigate crimes perpetuated partially
or entirely over the Internet. These types of crime are known as cybercrimes.
In order to conceal illegal online activity, criminals often use private
browsing features or browsers designed to provide total browsing privacy. The
use of private browsing is a common challenge faced in for example child
exploitation investigations, which usually originate on the Internet. Although
private browsing features are not designed specifically for criminal activity,
they have become a valuable tool for criminals looking to conceal their online
activity. As such, Technological Crime units often focus their forensic
analysis on thoroughly examining the web history on a computer. Private
browsing features and browsers often require a more in-depth, post mortem
analysis. This often requires the use of multiple tools, as well as different
forensic approaches to uncover incriminating evidence. This evidence may be
required in a court of law, where analysts are often challenged both on their
findings and on the tools and approaches used to recover evidence. However,
there are very few research on evaluating of private browsing in terms of
privacy preserving as well as forensic acquisition and analysis of privacy
preserving internet browsers. Therefore in this chapter, we firstly review the
private mode of popular internet browsers. Next, we describe the forensic
acquisition and analysis of Browzar, a privacy preserving internet browser and
compare it with other popular internet browser
Early star formation traced by the highest redshift quasars
The iron abundance relative to alpha-elements in the circumnuclear region of
quasars is regarded as a clock of the star formation history and, more
specifically, of the enrichment by SNIa. We investigate the iron abundance in a
sample of 22 quasars in the redshift range 3.0<z<6.4 by measuring their rest
frame UV FeII bump, which is shifted into the near-IR, and by comparing it with
the MgII 2798 flux. The observations were performed with a device that can
obtain near-IR spectra in the range 0.8-2.4 um in one shot, thereby enabling an
optimal removal of the continuum underlying the FeII bump. We detect iron in
all quasars including the highest redshift (z=6.4) quasar currently known. The
uniform observational technique and the wide redshift range allows a reliable
study of the trend of the FeII/MgII ratio with redshift. We find the FeII/MgII
ratio is nearly constant at all redshifts, although there is marginal evidence
for a higher FeII/MgII ratio in the quasars at z~6. If the FeII/MgII ratio
reflects the Fe/alpha abundance, this result suggests that the z~6 quasars have
already undergone a major episode of iron enrichment. We discuss the possible
implications of this finding for the star formation history at z>6. We also
detect a population of weak iron emitters at z~4.5, which are possibly hosted
in systems that evolved more slowly. Alternatively, the trend of the FeII/MgII
ratio at high redshift may reflect significantly different physical conditions
of the circumnuclear gas in such high redshift quasars.Comment: Replaced to match the accepted version (ApJL in press), 5 page
An Evaluation of a Maternal Health and Extreme Heat Exposure Training
Growing empirical evidence documents the potential risk of extreme heat exposure to pregnant individuals. These risks include adverse birth outcomes, such as preterm birth and low birth weight. Climate change will exacerbate extreme heat exposures to a large portion of the global population, and pregnant individuals need to understand the risks and protective measures needed. Maternal health workers are a key mechanism for conveying this information to pregnant individuals. The authors assess a training of maternal health workers in El Paso, Texas, through two research instruments. First, eight maternal health workers completed an educational workshop and consented to participation; pre- and post-test workshop data are reported. Second, and subsequent to the workshop, a focus group was undertaken with six maternal health workers; directed content analysis was used to synthesize and report patterns from this qualitative data. Assessments indicated that a training session can improve provider knowledge of maternal heatāhealth risks and can encourage providers to discuss heat risks with patients/clients. This pilot project offered an approach to raise awareness of extreme heat among maternal health workers. The authors encourage the development of similar trainings in other communities to improve the safety of pregnant individuals in warm regions and areas experiencing extreme heat
Motility of small nematodes in disordered wet granular media
The motility of the worm nematode \textit{Caenorhabditis elegans} is
investigated in shallow, wet granular media as a function of particle size
dispersity and area density (). Surprisingly, we find that the nematode's
propulsion speed is enhanced by the presence of particles in a fluid and is
nearly independent of area density. The undulation speed, often used to
differentiate locomotion gaits, is significantly affected by the bulk material
properties of wet mono- and polydisperse granular media for .
This difference is characterized by a change in the nematode's waveform from
swimming to crawling in dense polydisperse media \textit{only}. This change
highlights the organism's adaptability to subtle differences in local structure
and response between monodisperse and polydisperse media
Confirmation of the Luminous Blue Variable status of MWC 930
We present spectroscopic and photometric observations of the emission-line
star MWC 930 (V446 Sct) during its long-term optical brightening in 2006--2013.
Based on our earlier data we suggested that the object has features found in
Luminous Blue Variables (LBV), such as a high luminosity (~3 10^5 Lsun, a low
wind terminal velocity (~ 140 km/s), and a tendency to show strong brightness
variations (~1 mag over 20 years). For the last ~7 years it has been exhibiting
a continuous optical and near-IR brightening along with a change of the
emission-line spectrum appearance and cooling of the star's photosphere. We
present the object's --band light curve, analyze the spectral variations,
and compare the observed properties with those of other recognized Galactic
LBVs, such as AG Car and HR Car. Overall we conclude the MWC 930 is a bona fide
Galactic LBV that is currently in the middle of an S Dor cycle.Comment: 12 pages, 7 figure
Effects of the COVID-19 pandemic on medical students: a multicenter quantitative study
Ā© 2021, The Author(s). Background: The COVID-19 pandemic disrupted the United States (US) medical education system with the necessary, yet unprecedented Association of American Medical Colleges (AAMC) national recommendation to pause all student clinical rotations with in-person patient care. This study is a quantitative analysis investigating the educational and psychological effects of the pandemic on US medical students and their reactions to the AAMC recommendation in order to inform medical education policy. Methods: The authors sent a cross-sectional survey via email to medical students in their clinical training years at six medical schools during the initial peak phase of the COVID-19 pandemic. Survey questions aimed to evaluate studentsā perceptions of COVID-19ās impact on medical education; ethical obligations during a pandemic; infection risk; anxiety and burnout; willingness and needed preparations to return to clinical rotations. Results: Seven hundred forty-one (29.5%) students responded. Nearly all students (93.7%) were not involved in clinical rotations with in-person patient contact at the time the study was conducted. Reactions to being removed were mixed, with 75.8% feeling this was appropriate, 34.7% guilty, 33.5% disappointed, and 27.0% relieved. Most students (74.7%) agreed the pandemic had significantly disrupted their medical education, and believed they should continue with normal clinical rotations during this pandemic (61.3%). When asked if they would accept the risk of infection with COVID-19 if they returned to the clinical setting, 83.4% agreed. Students reported the pandemic had moderate effects on their stress and anxiety levels with 84.1% of respondents feeling at least somewhat anxious. Adequate personal protective equipment (PPE) (53.5%) was the most important factor to feel safe returning to clinical rotations, followed by adequate testing for infection (19.3%) and antibody testing (16.2%). Conclusions: The COVID-19 pandemic disrupted the education of US medical students in their clinical training years. The majority of students wanted to return to clinical rotations and were willing to accept the risk of COVID-19 infection. Students were most concerned with having enough PPE if allowed to return to clinical activities
Carbon supported CdSe nanocrystals
Insights to the mechanism of CdSe nanoparticle attachment to carbon nanotubes
following the hot injection method are discussed. It was observed that the
presence of water improves the nanotube coverage while Cl containing media are
responsible for the shape transformation of the nanoparticles and further
attachment to the carbon lattice. The experiments also show that the mechanism
taking place involves the right balance of several factors, namely, low
passivated nanoparticle surface, particles with well-defined crystallographic
facets, and interaction with an organics-free sp2 carbon lattice. Furthermore,
this procedure can be extended to cover graphene by quantum dots.Comment: 5 pages, 5 figure
Bayesian variable selection using partially observed categorical prior information in fine-mapping association studies
Several methods have been proposed to allow functional genomic information to inform prior distributions in Bayesian fineāmapping caseācontrol association studies. None of these methods allow the inclusion of partially observed functional genomic information. We use functional significance (FS) scores that combine information across multiple bioinformatics sources to inform our effect size prior distributions. These scores are not available for all singleānucleotide polymorphisms (SNPs) but by partitioning SNPs into naturally occurring FS score groups, we show how missing FS scores can easily be accommodated via finite mixtures of elicited priors. Most current approaches adopt a formal Bayesian variable selection approach and either limit the number of causal SNPs allowed or use approximations to avoid the need to explore the vast parameter space. We focus instead on achieving differential shrinkage of the effect sizes through prior scale mixtures of normals and use marginal posterior probability intervals to select candidate causal SNPs. We show via a simulation study how this approach can improve localisation of the causal SNPs compared to existing mutliāSNP fineāmapping methods. We also apply our approach to fineāmapping a region around the CASP8 gene using the iCOGS consortium breast cancer SNP data
The Public Health Exposome: A Population-Based, Exposure Science Approach to Health Disparities Research
The lack of progress in reducing health disparities suggests that new approaches are needed if we are to achieve meaningful, equitable, and lasting reductions. Current scientific paradigms do not adequately capture the complexity of the relationships between environment, personal health and population level disparities. The public health exposome is presented as a universal exposure tracking framework for integrating complex relationships between exogenous and endogenous exposures across the lifespan from conception to death. It uses a social-ecological framework that builds on the exposome paradigm for conceptualizing how exogenous exposures āget under the skinā. The public health exposome approach has led our team to develop a taxonomy and bioinformatics infrastructure to integrate health outcomes data with thousands of sources of exogenous exposure, organized in four broad domains: natural, built, social, and policy environments. With the input of a transdisciplinary team, we have borrowed and applied the methods, tools and terms from various disciplines to measure the effects of environmental exposures on personal and population health outcomes and disparities, many of which may not manifest until many years later. As is customary with a paradigm shift, this approach has far reaching implications for research methods and design, analytics, community engagement strategies, and research training
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