1,027 research outputs found
Uncovering complexity details in actigraphy patterns to differentiate the depressed from the non-depressed
While the negative association between physical activity and depression has been well established, it is unclear what precise characteristics of physical activity patterns explain this association. Complexity measures may identify previously unexplored aspects of objectively measured activity patterns, such as the extent to which individuals show repetitive periods of physical activity and the diversity in durations of such repetitive activity patterns. We compared the complexity levels of actigraphy data gathered over 4 weeks ([Formula: see text] data points each) for every individual, from non-depressed ([Formula: see text] ) and depressed ([Formula: see text] ) groups using recurrence plots. Significantly lower levels of complexity were detected in the actigraphy data from the depressed group as compared to non-depressed controls, both in terms of lower mean durations of periods of recurrent physical activity and less diversity in the duration of these periods. Further, diagnosis of depression was not significantly associated with mean activity levels or measures of circadian rhythm stability, and predicted depression status better than these
Passive sampling and benchmarking to rank HOC levels in the aquatic environment
The identification and prioritisation of water bodies presenting elevated levels of anthropogenic chemicals is a key aspect of environmental monitoring programmes. Albeit this is challenging owing to geographical scales, choice of indicator aquatic species used for chemical monitoring, and inherent need for an understanding of contaminant fate and distribution in the environment. Here, we propose an innovative methodology for identifying and ranking water bodies according to their levels of hydrophobic organic contaminants (HOCs) in water. This is based on a unique passive sampling dataset acquired over a 10-year period with silicone rubber exposures in surface water bodies across Europe. We show with these data that, far from point sources of contamination, levels of hexachlorobenzene (HCB) and pentachlorobenzene (PeCB) in water approach equilibrium with atmospheric concentrations near the air/water surface. This results in a relatively constant ratio of their concentrations in the water phase. This, in turn, allows us to (i) identify sites of contamination with either of the two chemicals when the HCB/PeCB ratio deviates from theory and (ii) define benchmark levels of other HOCs in surface water against those of HCB and/or PeCB. For two polychlorinated biphenyls (congener 28 and 52) used as model chemicals, differences in contamination levels between the more contaminated and pristine sites are wider than differences in HCB and PeCB concentrations endorsing the benchmarking procedure
BoxeR: Box-Attention for 2D and 3D Transformers
In this paper, we propose a simple attention mechanism, we call
box-attention. It enables spatial interaction between grid features, as sampled
from boxes of interest, and improves the learning capability of transformers
for several vision tasks. Specifically, we present BoxeR, short for Box
Transformer, which attends to a set of boxes by predicting their transformation
from a reference window on an input feature map. The BoxeR computes attention
weights on these boxes by considering its grid structure. Notably, BoxeR-2D
naturally reasons about box information within its attention module, making it
suitable for end-to-end instance detection and segmentation tasks. By learning
invariance to rotation in the box-attention module, BoxeR-3D is capable of
generating discriminative information from a bird's-eye view plane for 3D
end-to-end object detection. Our experiments demonstrate that the proposed
BoxeR-2D achieves state-of-the-art results on COCO detection and instance
segmentation. Besides, BoxeR-3D improves over the end-to-end 3D object
detection baseline and already obtains a compelling performance for the vehicle
category of Waymo Open, without any class-specific optimization. Code is
available at https://github.com/kienduynguyen/BoxeR.Comment: In Proceeding of CVPR'202
Evolution of surface gravity waves over a submarine canyon
The effects of a submarine canyon on the propagation of ocean surface waves
are examined with a three-dimensional coupled-mode model for wave propagation
over steep topography. Whereas the classical geometrical optics approximation
predicts an abrupt transition from complete transmission at small incidence
angles to no transmission at large angles, the full model predicts a more
gradual transition with partial reflection/transmission that is sensitive to
the canyon geometry and controlled by evanescent modes for small incidence
angles and relatively short waves. Model results for large incidence angles are
compared with data from directional wave buoys deployed around the rim and over
Scripps Canyon, near San Diego, California, during the Nearshore Canyon
Experiment (NCEX). Wave heights are observed to decay across the canyon by
about a factor 5 over a distance shorter than a wavelength. Yet, a spectral
refraction model predicts an even larger reduction by about a factor 10,
because low frequency components cannot cross the canyon in the geometrical
optics approximation. The coupled-mode model yields accurate results over and
behind the canyon. These results show that although most of the wave energy is
refractively trapped on the offshore rim of the canyon, a small fraction of the
wave energy 'tunnels' across the canyon. Simplifications of the model that
reduce it to the standard and modified mild slope equations also yield good
results, indicating that evanescent modes and high order bottom slope effects
are of minor importance for the energy transformation of waves propagating
across depth contours at large oblique angles
Taking piezoelectric microsystems from the laboratory to production
Reliable integration of piezoelectric thin films into silicon-based microsystems on an industrial scale is a key enabling technology for a wide range of future products. However, current knowledge in the field is mostly limited to the conditions and scale of academic laboratories. Thus, knowledge on performance, reliability and reproducibility of the films and methods at industrial level is scarce. The present study intends to contribute to the development of reliable technology for integration of piezoelectric thin films into MEMS on an industrial scale. A test wafer design that contained more than 500 multimorph cantilevers, bridges and membranes in the size range between 50 and 1,500 μm was developed. The active piezoelectric material was a ∼2 μm thin film of lead zirconate titanate (PZT) deposited by a state-of-the-art chemical solution deposition (CSD) procedure. Automated measurements of C(V) and dielectric dissipation factor at 1 kHz were made on more than 200 devices at various locations across the wafer surface. The obtained standard deviations were 4.5 and 11% for the permittivity and dissipation factor, respectively. Values for the transverse piezoelectric charge coefficient, e 31,f, of up to −15.1 C/m2 were observed. Fatigue tests with a 5 kHz signal applied to a typical cantilever at ± 25 V led to less than 10% reduction of the remanent polarisation after 2 × 107 bipolar cycles. Cantilever out-of-plane deflection at zero field measured after poling was less than 1.1% for a typical 800 μm cantilever
Meaning above the head: combinatorial constraints on the visual vocabulary of comics
“Upfixes” are “visual morphemes” originating in comics where an element floats above a character’s head (ex. lightbulbs or gears). We posited that, similar to constructional lexical schemas in language, upfixes use an abstract schema stored in memory, which constrains upfixes to locations above the head and requires them to “agree” with their accompanying facial expressions. We asked participants to rate and interpret both conventional and unconventional upfixes that either matched or mismatched their facial expression (Experiment 1) and/or were placed either above or beside the head (Experiment 2). Interpretations and ratings of conventionality and face–upfix matching (Experiment 1) along with overall comprehensibility (Experiment 2) suggested that both constraints operated on upfix understanding. Because these constraints modulated both conventional and unconventional upfixes, these findings support that an abstract schema stored in long-term memory allows for generalisations beyond memorised individual items
The added value of daily diary data in 1- and 3-year prediction of psychopathology and psychotic experiences in individuals at risk for psychosis
This study aimed to assess whether adding information on psychological experiences derived from a daily diary to baseline cross-sectional data could improve short- (1-year) and long-term (3-years) prediction of psychopathology and positive psychotic experiences (PEs). We used 90-day daily diary data from 96 individuals in early subclinical risk stages for psychosis. Stepwise linear regression models were built for psychopathology and PEs at 1- and 3-years follow-up, adding: (1) baseline questionnaires, (2) the mean and variance of daily psychological experiences, and (3) individual symptom network density. We assessed whether similar results could be achieved with a subset of the data (7-14- and 30-days). The mean and variance of the diary improved model prediction of short- and long-term psychopathology and PEs, compared to prediction based on baseline questionnaires solely. Similar results were achieved with 7-14- and 30-day subsets. Symptom network density did not improve model prediction except for short-term prediction of PEs. Simple metrics, i.e., the mean and variance from 7 to 14 days of daily psychological experiences assessments, can improve short- and long-term prediction of both psychopathology and PEs in individuals in early subclinical stages for psychosis. Diary data could be a valuable addition to clinical risk prediction models for psychopathology development.</p
Het verloop van de landbouwkundige en industriële kwaliteit in verschillende knolgroottesorteringen van twee zetmeelaardappelrassen gedurende het groeiseizoen : verslag van de veldproeven KB 9055 en KP 9112, werkdocument over het vierde proefjaar 2002
Knol- en zetmeelopbrengst van aardappelen worden beïnvloed door de rooidatum van het gewas en het ras. Naarmate later wordt geoogst, neemt zowel de verse knolopbrengst als het onderwatergewicht (zetmeelgehalte) van de knollen toe. Op beide locaties liggen de onderwater- en uitbetalingsgewichten bij het ras Seresta hoger dan bij Karakter
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