851 research outputs found
Predictive sensor method and apparatus
A microprocessor and electronics package employing predictive methodology was developed to accelerate the response time of slowly responding hydrogen sensors. The system developed improved sensor response time from approximately 90 seconds to 8.5 seconds. The microprocessor works in real-time providing accurate hydrogen concentration corrected for fluctuations in sensor output resulting from changes in atmospheric pressure and temperature. Following the successful development of the hydrogen sensor system, the system and predictive methodology was adapted to a commercial medical thermometer probe. Results of the experiment indicate that, with some customization of hardware and software, response time improvements are possible for medical thermometers as well as other slowly responding sensors
Collaboration in the age of personalised mass(ive) education
In the paper we explore a number of issues we believe challenge some current notions of collaboration. We explore tensions arising from the increased interest in personalised open learning, and how this challenges, but also offers new ways of conceptualising collaboration towards group-organisations that are more nomadic entanglements of shifting participation
Planetary population synthesis coupled with atmospheric escape: a statistical view of evaporation
We apply hydrodynamic evaporation models to different synthetic planet
populations that were obtained from a planet formation code based on a
core-accretion paradigm. We investigated the evolution of the planet
populations using several evaporation models, which are distinguished by the
driving force of the escape flow (X-ray or EUV), the heating efficiency in
energy-limited evaporation regimes, or both. Although the mass distribution of
the planet populations is barely affected by evaporation, the radius
distribution clearly shows a break at approximately 2 . We find
that evaporation can lead to a bimodal distribution of planetary sizes (Owen &
Wu 2013) and to an "evaporation valley" running diagonally downwards in the
orbital distance - planetary radius plane, separating bare cores from low-mass
planet that have kept some primordial H/He. Furthermore, this bimodal
distribution is related to the initial characteristics of the planetary
populations because low-mass planetary cores can only accrete small primordial
H/He envelopes and their envelope masses are proportional to their core masses.
We also find that the population-wide effect of evaporation is not sensitive to
the heating efficiency of energy-limited description. However, in two extreme
cases, namely without evaporation or with a 100\% heating efficiency in an
evaporation model, the final size distributions show significant differences;
these two scenarios can be ruled out from the size distribution of
candidates.Comment: Accepted for publication in ApJ; 24 pages, 16 figure
Toward Whole-Brain Minimally-Invasive Vascular Imaging
Imaging the brain vasculature can be critical for cerebral perfusion
monitoring in the context of neurocritical care. Although ultrasensitive
Doppler (UD) can provide good sensitivity to cerebral blood volume (CBV) in a
large field of view, it remains difficult to perform through the skull. In this
work, we investigate how a minimally invasive burr hole, performed for
intracranial pressure (ICP) monitoring, could be used to map the entire brain
vascular tree. We explored the use of a small motorized phased array probe with
a non-implantable preclinical prototype in pigs. The scan duration (18 min) and
coverage (62 12 % of the brain) obtained allowed global CBV variations
detection (relative in brain Dopplerdecrease =-3[-4-+16]% \& Dopplerincrease. =
+1[-3-+15]%, n = 6 \& 5) and stroke detection (relative in core Dopplerstroke.
=-25%, n = 1). This technology could one day be miniaturized to be implanted
for brain perfusion monitoring in neurocritical care
Science Hackathons for Cyberphysical System Security Research: Putting CPS testbed platforms to good use
A challenge is to develop cyber-physical system scenarios that reflect the
diversity and complexity of real-life cyber-physical systems in the research
questions that they address. Time-bounded collaborative events, such as
hackathons, jams and sprints, are increasingly used as a means of bringing
groups of individuals together, in order to explore challenges and develop
solutions. This paper describes our experiences, using a science hackathon to
bring individual researchers together, in order to develop a common use-case
implemented on a shared CPS testbed platform that embodies the diversity in
their own security research questions. A qualitative study of the event was
conducted, in order to evaluate the success of the process, with a view to
improving future similar events
Electronic clinical predictive thermometer using logarithm for temperature prediction
A thermometer that rapidly predicts body temperature based on the temperature signals received from a temperature sensing probe when it comes into contact with the body. The logarithms of the differences between the temperature signals in a selected time frame are determined. A line is fit through the logarithms and the slope of the line is used as a system time constant in predicting the final temperature of the body. The time constant in conjunction with predetermined additional constants are used to compute the predicted temperature. Data quality in the time frame is monitored and if unacceptable, a different time frame of temperature signals is selected for use in prediction. The processor switches to a monitor mode if data quality over a limited number of time frames is unacceptable. Determining the start time on which the measurement time frame for prediction is based is performed by summing the second derivatives of temperature signals over time frames. When the sum of second derivatives in a particular time frame exceeds a threshold, the start time is established
Alexithymia Is Associated With Deficits in Visual Search for Emotional Faces in Clinical Depression
Background: The concept of alexithymia is characterized by difficulties identifying and
describing one’s emotions. Alexithymic individuals are impaired in the recognition of
others’ emotional facial expressions. Alexithymia is quite common in patients suffering
from major depressive disorder. The face-in-the-crowd task is a visual search paradigm
that assesses processing of multiple facial emotions. In the present eye-tracking study,
the relationship between alexithymia and visual processing of facial emotions was
examined in clinical depression.
Materials and Methods: Gaze behavior and manual response times of 20 alexithymic
and 19 non-alexithymic depressed patients were compared in a face-in-the-crowd task.
Alexithymia was empirically measured via the 20-item Toronto Alexithymia-Scale. Angry,
happy, and neutral facial expressions of different individuals were shown as target and
distractor stimuli. Our analyses of gaze behavior focused on latency to the target face,
number of distractor faces fixated before fixating the target, number of target fixations,
and number of distractor faces fixated after fixating the target.
Results: Alexithymic patients exhibited in general slower decision latencies compared
to non-alexithymic patients in the face-in-the-crowd task. Patient groups did not differ
in latency to target, number of target fixations, and number of distractors fixated prior
to target fixation. However, after having looked at the target, alexithymic patients fixated
more distractors than non-alexithymic patients, regardless of expression condition.
Discussion: According to our results, alexithymia goes along with impairments in
visual processing of multiple facial emotions in clinical depression. Alexithymia appears
to be associated with delayed manual reaction times and prolonged scanning after
the first target fixation in depression, but it might have no impact on the early search
phase. The observed deficits could indicate difficulties in target identification and/or
decision-making when processing multiple emotional facial expressions. Impairments
of alexithymic depressed patients in processing emotions in crowds of faces seem not
limited to a specific affective valence. In group situations, alexithymic depressed patients
might be slowed in processing interindividual differences in emotional expressions
compared with non-alexithymic depressed patients. This could represent a disadvantage
in understanding non-verbal communication in groups
Causes, Consequences, and Policy Responses to the Migration of Health Workers: Key Findings from India
Background: This study sought to better understand the drivers of skilled health professional migration, its consequences, and the various strategies countries have employed to mitigate its negative impacts. The study was conducted in four countries—Jamaica, India, the Philippines, and South Africa—that have historically been “sources” of health workers migrating to other countries. The aim of this paper is to present the findings from the Indian portion of the study.
Methods: Data were collected using surveys of Indian generalist and specialist physicians, nurses, midwives, dentists, pharmacists, dieticians, and other allied health therapists. We also conducted structured interviews with key stakeholders representing government ministries, professional associations, regional health authorities, health care facilities, and educational institutions. Quantitative data were analyzed using descriptive statistics and regression models. Qualitative data were analyzed thematically.
Results: Shortages of health workers are evident in certain parts of India and in certain specialty areas, but the degree and nature of such shortages are difficult to determine due to the lack of evidence and health information. The relationship of such shortages to international migration is not clear. Policy responses to health worker migration are also similarly embedded in wider processes aimed at health workforce management, but overall, there is no clear policy agenda to manage health worker migration. Decision-makers in India present conflicting options about the need or desirability of curtailing migration.
Conclusions: Consequences of health work migration on the Indian health care system are not easily discernable from other compounding factors. Research suggests that shortages of skilled health workers in India must be examined in relation to domestic policies on training, recruitment, and retention rather than viewed as a direct consequence of the international migration of health workers
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