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Though compact polarimetric approaches have been developed and applied in space and geo researching systems they have not been taken into consideration in automotive applications, yet. A sensor system has been designed to conduct polarimetric measurements in the 77 GHz frequency band, which is permitted for automotive usage. This system is able to transceive linearly as well as circularly polarized electromagnetic continuous waves. Depending on the case of application, the frequency output can be set statically or modulated over time within adjustable parameters. Hence, a variety of compact polarimetric modes can be performed and compared with full polarimetric approaches. Two compact polarimetric modes, dual-circular polarimetric mode, and circular-transmit-linear-receive, will be introduced and applied in this contribution. Their operability in this frequency range will be investigated after the microstrip antennas as well as the beam focusing dielectrical lense are characterized. Finally, results of a realistical measurement set-up will confirm the practicability of compact polarimetric approaches for double bounce recognition.
Finding the boundaries of linguistic variants and studying transitions between variants are key interests in classical linguistic geography. However, the definition of boundaries in areal linguistics is vague, and a quantitative characterization of transitions at the interface between dialectal variants is missing. We conceptualize these transitions as gradients, aiming to quantitatively account for the transition patterns which are traditionally only implicitly inferred from visualizations. Fitting of logistic functions in different spatial scopes (profiles as well as surfaces) is proposed as an approach to model the transition at the interface between the dominant usage areas of dialectal variants. Logistic functions can accommodate the breadth of boundary concepts, ranging from sharp isoglosses to transitions with different gradualities. The parameters of the fitted logistic models as well as supplementary measures then allow for the quantitative characterization and comparison of transitions across variables. To demonstrate the proposed methodology, we use Swiss German syntactic data on dialectal variables with a single transition zone.
In the actual context of terrorism targeting children and families, it seems essential to describe different experiences of pediatric psychological emergency devices after such unexpected mass trauma. Here we testify our experience of the psychological emergency care setup dedicated to children and families during the first 48 hours after the terrorist attack of Nice, France, on July 14, 2016. Activated within the hour following the attack, the device included two child psychiatry teams turning over each day, receiving at least 163 individuals (99 children and 64 adults) within the first 2 days. (Disaster Med Public Health Preparedness. 2019;13:144–146)
Using data from a Swiss German dialect syntax survey, this study aims to explore, in a spatially differentiated manner, the correlation between dialectal variation and geographic distances. A linguistic distance was expressed by a measure aggregated from 60 survey questions. To operationalize the possibility of language contact, Euclidean distance, as well as travel times in 2000, 1950 and 1850 between survey sites were used. Going beyond previous work by others, we also explore the covariation of geographic and linguistic distances at the local level, focusing on spatial subsets and individual survey sites, thus being able to paint a more differentiated picture. With the diverse physical landscape of Switzerland making an impact on potential language contact, we find that travel times are a better predictor than Euclidean distance for the syntactic variation in Swiss German dialects. However, on the local scale the difference is not always significant, depending on prevalent topography.
We describe a project to retrieve a 948m deep ice core from Berkner Island, Antarctica. Using relatively lightweight logistics and a small team, the drilling operation over three austral summer seasons used electromechanical drilling technology, described in detail, from a covered shallow pit and a fluid-filled borehole. A basal temperature well below pressure-melting point meant that no drilling problems were encountered when approaching the bed and the borehole penetrated through to the base of the ice sheet, and sediment was retrieved from beneath the ice.
A method to assess firn compaction using data collected with the Airborne SAR (Synthetic Aperture Radar)/Interferometric Radar Altimeter System (ASIRAS) is developed. For this, we develop a dynamical firn-compaction model that includes meltwater retention. Based on the ASIRAS data, which show internal layers as annual horizons in the uppermost firn, the method relies on inferring the age/ depth (internal layers) information from the radar data using a Monte Carlo inversion technique to tune in parallel both the firn model and the atmospheric forcing parameters (temperature and accumulation). The model is validated against two firn cores, and it is shown that applying both firn densities and age/ depth information for the inversion gives the most accurate understanding of model biases. The method is then applied to a 67 km section of the EGIG line forced by atmospheric output from a regional climate model using only age/depth information in the inversion step. The layers traced by the ASIRAS data are modeled with a root-mean-square error of 9 cm, which is within the estimated error of the layer tracing. This gives us confidence in applying observed annual layering from firn radar data to assess firn compaction; however, the study also indicates that our firn-model-tuning parameters are site-dependent and cannot be parameterized by temperature and accumulation alone.
We consider a server with large capacity delivering video files encoded in various resolutions. We assume that the system is under saturation in the sense that the total demand exceeds the server capacity C. In such a case, requests may be rejected. For the policies considered in this paper, instead of rejecting a video request, it is downgraded. When the occupancy of the server is above some value C0 < C, the server delivers the video at a minimal bit rate. The quantity C0 is the bit rate adaptation threshold. For these policies, request blocking is thus replaced with bit rate adaptation. Under the assumptions of Poisson request arrivals and exponential service times, we show that, by rescaling the system, a process associated with the occupancy of the server converges to some limiting process whose invariant distribution is computed explicitly. This allows us to derive an asymptotic expression of the key performance measure of such a policy, namely the equilibrium probability that a request is transmitted at requested bitrate. Numerical applications of these results are presented.
Oral glucose tolerance and insulin sensitivity are common measures, but are determined using various blood sampling methods, employed under many different experimental conditions. This study established whether measures of oral glucose tolerance and oral glucose-derived insulin sensitivity (insulin sensitivity indices; ISI) differ when calculated from venous v. arterialised blood. Critically, we also established whether any differences between sampling methods are consistent across distinct metabolic conditions (after rest v. after exercise). A total of ten healthy men completed two trials in a randomised order, each consisting of a 120-min oral glucose tolerance test (OGTT), either at rest or post-exercise. Blood was sampled simultaneously from a heated hand (arterialised) and an antecubital vein of the contralateral arm (venous). Under both conditions, glucose time-averaged AUC was greater from arterialised compared with venous plasma but importantly, this difference was larger after rest relative to after exercise (0·99 (sd 0·46) v. 0·56 (sd 0·24) mmol/l, respectively; P<0·01). OGTT-derived ISIMatsuda and ISICederholm were lower when calculated from arterialised relative to venous plasma and the arterialised–venous difference was greater after rest v. after exercise (ISIMatsuda: 1·97 (sd 0·81) v. 1·35 (sd 0·57) arbitrary units (au), respectively; ISICederholm : 14·76 (sd 7·83) v. 8·70 (sd 3·95) au, respectively; both P<0·01). Venous blood provides lower postprandial glucose concentrations and higher estimates of insulin sensitivity, compared with arterialised blood. Most importantly, these differences between blood sampling methods are not consistent after rest v. post-exercise, preventing standardised venous-to-arterialised corrections from being readily applied.
Stratified shear flows occur in many geophysical contexts, from oceanic overflows and river estuaries to wind-driven thermocline layers. We explore a turbulent wall-bounded shear flow of lighter miscible fluid into a quiescent fluid of higher density with a range of Richardson numbers
$0.05\lesssim Ri\lesssim 1$
. In order to find a stability parameter that allows close comparison with linear theory and with idealized experiments and numerics, we investigate different definitions of
. We find that a gradient Richardson number defined on fluid interface sections where there is no overturning at or adjacent to the maximum density gradient position provides an excellent stability parameter, which captures the Miles–Howard linear stability criterion. For small
the flow exhibits robust Kelvin–Helmholtz instability, whereas for larger
interfacial overturning is more intermittent with less frequent Kelvin–Helmholtz events and emerging Holmboe wave instability consistent with a thicker velocity layer compared with the density layer. We compute the perturbed fraction of interface as a quantitative measure of the flow intermittency, which is approximately 1 for the smallest
but decreases rapidly as
increases, consistent with linear theory. For the perturbed regions, we use the Thorpe scale to characterize the overturning properties of these flows. The probability distribution of the non-zero Thorpe length yields a universal exponential form, suggesting that much of the overturning results from increasingly intermittent Kelvin–Helmholtz instability events. The distribution of turbulent kinetic energy, conditioned on the intermittency fraction, has a similar form, suggesting an explanation for the universal scaling collapse of the Thorpe length distribution.
In order to verify the relative dating based on pot type morphology and decoration of the Swifterbant pottery collected at the Final Mesolithic site of Doel “Deurganckdok” (Belgium) and of the Late Iron Age pottery excavated at Grijpskerke (the Netherlands), direct radiocarbon dates were obtained on charred food residue preserved on the inner surface of numerous potsherds. In addition, a number of indirect 14C dates were obtained from samples of organic material. In the case of Doel, the results indicate an important incompatibility between the charred food residue dates and the other dates, the former being systematically older. This difference may be explained by a reservoir effect of the charred food residue, caused by the processing of (freshwater) fish. The 14C dates for the Grijpskerke site are in agreement between the charred food residue and the organic material. The stable isotopes of the charred food residue were analyzed to demonstrate fish processing in the pottery, but the results were inconclusive.
The details of current and past star formation episodes and the stellar content of the central parsecs of our galaxy are still not very well known (Mezger et al., 1996). We have therefore begun an observing program to study star formation processes in the nuclear bulge. Here we discuss the technical aspects of this program, while the scientific goals are presented by Zylka et al. (1997).
We describe a hybrid pixel array detector (electron microscope pixel array detector, or EMPAD) adapted for use in electron microscope applications, especially as a universal detector for scanning transmission electron microscopy. The 128×128 pixel detector consists of a 500 µm thick silicon diode array bump-bonded pixel-by-pixel to an application-specific integrated circuit. The in-pixel circuitry provides a 1,000,000:1 dynamic range within a single frame, allowing the direct electron beam to be imaged while still maintaining single electron sensitivity. A 1.1 kHz framing rate enables rapid data collection and minimizes sample drift distortions while scanning. By capturing the entire unsaturated diffraction pattern in scanning mode, one can simultaneously capture bright field, dark field, and phase contrast information, as well as being able to analyze the full scattering distribution, allowing true center of mass imaging. The scattering is recorded on an absolute scale, so that information such as local sample thickness can be directly determined. This paper describes the detector architecture, data acquisition system, and preliminary results from experiments with 80–200 keV electron beams.
Although non-drug interventions are widely used in patients with Alzheimer's disease, few large scale randomized trials involving a long-term intervention and several cognitive-oriented approaches have been carried out. ETNA3 trial compares the effect of cognitive training, reminiscence therapy, and an individualized cognitive rehabilitation program in Alzheimer's disease to usual care.
This is a multicenter (40 French clinical sites) randomized, parallel-group trial, with a two-year follow-up comparing groups receiving standardized programs of cognitive training (group sessions), reminiscence therapy (group sessions), individualized cognitive rehabilitation program (individual sessions), and usual care (reference group). Six hundred fifty-three outpatients with Alzheimer's disease were recruited. The primary efficacy outcome was the rate of survival without moderately severe to severe dementia at two years. Secondary outcomes were cognitive impairment, functional disability, behavioral disturbance, apathy, quality of life, depression, caregiver's burden, and resource utilization.
No impact on the primary efficacy measure was evidenced. For the two group interventions (i.e. cognitive training and reminiscence), none of the secondary outcomes differed from usual care. The larger effect was seen with individualized cognitive rehabilitation in which significantly lower functional disability and a six-month delay in institutionalization at two years were evidenced.
These findings challenge current management practices of Alzheimer's patients. While cognitive-oriented group therapies have gained popularity, this trial does not show improvement for the patients. The individualized cognitive rehabilitation intervention provided clinically significant results. Individual interventions should be considered to delay institutionalization in Alzheimer's disease.
Recently collected specimens of the crustose lichen Melaspilea demissa from south-eastern USA have been compared with those of Melaspilea spp. previously determined from North America. A review of both the historical and contemporary treatments of this species is provided. A lectotype was selected from the type collection of M. demissa in FH and is here proposed as it best matches incomplete citations in the original treatment. We also discuss the nomenclatural and taxonomic status of the name Opegrapha cymbiformis var. deformis (considered a synonym of M. gibberulosa). North American specimens of M. gibberulosa were found to be misidentifications, as were specimens attributed to M. lentiginosula, M. mesophlebia and M. octomera. We therefore recommend that these species be removed from the North American lichen checklist. We also present a key to North American Melaspilea.
While it is well known that posttraumatic stress disorder (PTSD) is characterized by heterogeneous symptom clusters, little is known about predominant typologies of PTSD symptoms in older adults.
Latent profile analyses (LPAs) were employed to evaluate predominant typologies of PTSD symptoms in a sample of 164 treatment-seeking older adults with childhood war-related trauma. Multinomial logistic regressions were conducted to evaluate predictors of class membership.
LPAs revealed that a 3-class solution best fit the data. These included an Intermediate Disturbance class (50.0%) and two Pervasive Disturbance classes, which differed with respect to severity of avoidance symptoms (Pervasive Disturbance-Low Avoidance: 33.5%, Pervasive Disturbance-High Avoidance: 16.5%). A greater number of traumatic events predicted membership in the Pervasive Disturbance classes. The Pervasive Disturbance-Low Avoidance class had a higher level of education than the Pervasive Disturbance-High Avoidance class. Compared to the Intermediate Disturbance class, the Pervasive Disturbance classes had the highest levels of depression, anxiety and somatization symptoms.
These results suggest that PTSD in treatment-seeking older adults may be characterized by three predominant typologies, which are differentiated by overall severity and avoidance symptoms, lifetime trauma burden, education level, and comorbid depression, anxiety, and somatization symptoms. These results underscore the importance of considering heterogeneity in the phenotypic presentation of PTSD in assessment and treatment approaches for this disorder in older adults.