157 research outputs found
Interferometric lensless imaging: rank-one projections of image frequencies with speckle illuminations
Lensless illumination single-pixel imaging with a multicore fiber (MCF) is a
computational imaging technique that enables potential endoscopic observations
of biological samples at cellular scale. In this work, we show that this
technique is tantamount to collecting multiple symmetric rank-one projections
(SROP) of an interferometric matrix--a matrix encoding the spectral content of
the sample image. In this model, each SROP is induced by the complex sketching
vector shaping the incident light wavefront with a spatial light modulator
(SLM), while the projected interferometric matrix collects up to image
frequencies for a -core MCF. While this scheme subsumes previous sensing
modalities, such as raster scanning (RS) imaging with beamformed illumination,
we demonstrate that collecting the measurements of random SLM
configurations--and thus acquiring SROPs--allows us to estimate an image of
interest if and scale log-linearly with the image sparsity level This
demonstration is achieved both theoretically, with a specific restricted
isometry analysis of the sensing scheme, and with extensive Monte Carlo
experiments. On a practical side, we perform a single calibration of the
sensing system robust to certain deviations to the theoretical model and
independent of the sketching vectors used during the imaging phase.
Experimental results made on an actual MCF system demonstrate the effectiveness
of this imaging procedure on a benchmark image.Comment: 13 pages, keywords: lensless imaging, rank-one projections,
interferometric matrix, inverse problem, computational imaging, single-pixe
Integrated multipoint-laser endoscopic airway measurements by transoral approach
Objectives: Optical and technical characteristics usually do not allow objective endoscopic distance measurements. So far no standardized method for endoscopic distance measurement is available. The aim of this study was to evaluate the feasibility and accuracy of transoral airway measurements with a multipoint-laser endoscope. Methods: The semirigid endoscope includes a multipoint laser measurement system that projects 49 laser points (wavelength 639 nm, power < 5mW) into the optical axis of the endoscopic view. Distances, areas, and depths can be measured in real-time. Transoral endoscopic airway measurements were performed on nine human cadavers, which were correlated with CT measurements. Results: The preliminary experiment showed an optimum distance between the endoscope tip and the object of 5 to 6 cm. There was a mean measurement error of 3.26% ±
2.53%. A Spearman correlation coefficient of 0.95
Recolonizing gray wolves increase parasite infection risk in their prey
The recent recolonization of Central Europe by the European gray wolf (Canis
lupus) provides an opportunity to study the dynamics of parasite transmission
for cases when a definitive host returns after a phase of local extinction. We
investigated whether a newly established wolf population increased the
prevalence of those parasites in ungulate intermediate hosts representing wolf
prey, whether some parasite species are particularly well adapted to wolves,
and the potential basis for such adaptations. We recorded Sarcocystis species
richness in wolves and Sarcocystis prevalence in ungulates harvested in study
sites with and without permanent wolf presence in Germany using microscopy and
DNA metabarcoding. Sarcocystis prevalence in red deer (Cervus elaphus) was
significantly higher in wolf areas (79.7%) than in control areas (26.3%) but
not in roe deer (Capreolus capreolus) (97.2% vs. 90.4%) or wild boar (Sus
scrofa) (82.8% vs. 64.9%). Of 11 Sarcocystis species, Sarcocystis taeniata and
Sarcocystis grueneri occurred more often in wolves than expected from the
Sarcocystis infection patterns of ungulate prey. Both Sarcocystis species
showed a higher increase in prevalence in ungulates in wolf areas than other
Sarcocystis species, suggesting that they are particularly well adapted to
wolves, and are examples of âwolf specialistsâ. Sarcocystis species richness
in wolves was significantly higher in pups than in adults. âWolf specialistsâ
persisted during wolf maturation. The results of this study demonstrate that
(1) predatorâprey interactions influence parasite prevalence, if both predator
and prey are part of the parasite life cycle, (2) mesopredators do not
necessarily replace the apex predator in parasite transmission dynamics for
particular parasites of which the apex predator is the definitive host, even
if mesoâ and apex predators were from the same taxonomic family (here:
Canidae, e.g., red foxes Vulpes vulpes), and (3) ageâdependent immune
maturation contributes to the control of protozoan infection in wolves
Chromium-based bcc-superalloys strengthened by iron supplements
Chromium alloys are being considered for next-generation concentrated solar power applications operating > 800 °C. Cr offers advantages in melting point, cost, and oxidation resistance. However, improvements in mechanical performance are needed. Here, Cr-based body-centred-cubic (bcc) alloys of the type Cr(Fe)-NiAl are investigated, leading to âbcc-superalloysâ comprising a bcc-Cr(Fe) matrix (ÎČ) strengthened by ordered-bcc NiAl intermetallic precipitates (ÎČâ), with iron additions to tailor the precipitate volume fraction and mechanical properties at high temperatures. Computational design using CALculation of PHAse Diagram (CALPHAD) predicts that Fe increases the solubility of Ni and Al, increasing precipitate volume fraction, which is validated experimentally. Nano-scale, highly-coherent B2-NiAl precipitates with lattice misfit ⌠0.1% are formed in the Cr(Fe) matrix. The Cr(Fe)-NiAl A2-B2 alloys show remarkably low coarsening rate (âŒ102 nm3/h at 1000 °C), outperforming ferritic-superalloys, cobalt- and nickel-based superalloys. Low interfacial energies of ⌠40/20 mJ/m2 at 1000/1200 °C are determined based on the coarsening kinetics. The low coarsening rates are principally attributed to the low solubility of Ni and Al in the Cr matrix. The alloys show high compressive yield strength of âŒ320 MPa at 1000 °C. The Fe-modified alloy exhibits resistance to age softening, related to the low coarsening rate as well as the relatively stable Orowan strengthening as a function of precipitate radius. Microstructure tailoring with Fe additions offers a new design route to improve the balance of properties in âCr-superalloysâ, accelerating their development as a new class of high-temperature materials
Chromium-based bcc-superalloys strengthened by iron supplements
Chromium alloys are being considered for next-generation concentrated solar power applications operating > 800 °C. Cr offers advantages in melting point, cost, and oxidation resistance. However, improvements in mechanical performance are needed. Here, Cr-based body-centred-cubic (bcc) alloys of the type Cr(Fe)-NiAl are investigated, leading to âbcc-superalloysâ comprising a bcc-Cr(Fe) matrix (ÎČ) strengthened by ordered-bcc NiAl intermetallic precipitates (ÎČâ), with iron additions to tailor the precipitate volume fraction and mechanical properties at high temperatures. Computational design using CALculation of PHAse Diagram (CALPHAD) predicts that Fe increases the solubility of Ni and Al, increasing precipitate volume fraction, which is validated experimentally. Nano-scale, highly-coherent B2-NiAl precipitates with lattice misfit ⌠0.1% are formed in the Cr(Fe) matrix. The Cr(Fe)-NiAl A2-B2 alloys show remarkably low coarsening rate (âŒ102 nm3/h at 1000 °C), outperforming ferritic-superalloys, cobalt- and nickel-based superalloys. Low interfacial energies of ⌠40/20 mJ/m2 at 1000/1200 °C are determined based on the coarsening kinetics. The low coarsening rates are principally attributed to the low solubility of Ni and Al in the Cr matrix. The alloys show high compressive yield strength of âŒ320 MPa at 1000 °C. The Fe-modified alloy exhibits resistance to age softening, related to the low coarsening rate as well as the relatively stable Orowan strengthening as a function of precipitate radius. Microstructure tailoring with Fe additions offers a new design route to improve the balance of properties in âCr-superalloysâ, accelerating their development as a new class of high-temperature materials
Practices to support co-design processes: A case-study of co-designing a program for children with parents with a mental health problem in the Austrian region of Tyrol
Forms of collaborative knowledge production, such as community-academic partnerships (CAP), have been increasingly used in health care. However, instructions on how to deliver such processes are lacking. We aim to identify practice ingredients for one element within a CAP, a 6-month co-design process, during which 26 community- and 13 research-partners collaboratively designed an intervention programme for children whose parent have a mental illness. Using 22 published facilitating and hindering factors for CAP as the analytical framework, eight community-partners reflected on the activities which took place during the co-design process. From a qualitative content analysis of the data, we distilled essential practices for each CAP factor. Ten community- and eight research-partners revised the results and co-authored this article. We identified 36 practices across the 22 CAP facilitating or hindering factors. Most practices address more than one factor. Many practices relate to workshop design, facilitation methods, and relationship building. Most practices were identified for facilitating âtrust among partnersâ, âshared visions, goals and/or missionsâ, âeffective/frequent communicationâ, and âwell-structured meetingsâ. Fewer practices were observed for âeffective conflict resolutionâ, âpositive community impactâ and for avoiding âexcessive funding pressure/control strugglesâ and âhigh burden of activitiesâ. Co-designing a programme for mental healthcare is a challenging process that requires skills in process management and communication. We provide practice steps for delivering co-design activities. However, practitioners may have to adapt them to different cultural contexts. Further research is needed to analyse whether co-writing with community-partners results in a better research output and benefits for participants
Dynamics in Liver Stiffness Measurements Predict Outcomes in Advanced Chronic Liver Disease
Background & Aims:Liver stiffness measurements (LSMs) provide an opportunity to monitor liver disease progression and regression noninvasively. We aimed to determine the prognostic relevance of LSM dynamics over time for liver-related events and death in patients with chronic liver disease. Methods:Patients with chronic liver disease undergoing 2 or more reliable LSMs at least 180 days apart were included in this retrospective cohort study and stratified at baseline (BL) as nonadvanced chronic liver disease (non-ACLD, BL-LSM < 10 kPa), compensated ACLD (cACLD; BL-LSM â„ 10 kPa), and decompensated ACLD. Data on all consecutive LSMs and clinical outcomes were collected. Results: There were 2508 patients with 8561 reliable LSMs (3 per patient; interquartile range, 2â4) included: 1647 (65.7%) with non-ACLD, 757 (30.2%) with cACLD, and 104 (4.1%) with decompensated ACLD. Seven non-ACLD patients (0.4%) and 83 patients with cACLD (10.9%) developed hepatic decompensation (median follow-up, 71 months). A 20% increase in LSM at any time was associated with an approximately 50% increased risk of hepatic decompensation (hazard ratio, 1.58; 95% CI, 1.41â1.79; P <.001) and liver-related death (hazard ratio, 1.45; 95% CI, 1.28â1.68; P <.001) in patients with cACLD. LSM dynamics yielded a high accuracy to predict hepatic decompensation in the following 12 months (area under the receiver operating characteristics curve = 0.933). The performance of LSM dynamics was numerically better than dynamics in Fibrosis-4 score (0.873), Model for End-Stage Liver Disease (0.835), and single time-point LSM (BL-LSM: 0.846; second LSM: 0.880). Any LSM decrease to <20 kPa identified patients with cACLD with a substantially lower risk of hepatic decompensation (hazard ratio, 0.13; 95% CI, 0.07â0.24). If reliable, LSM also confers prognostic information in decompensated ACLD. Conclusions: Repeating LSM enables an individual and updated risk assessment for decompensation and liver-related mortality in ACLD.</p
Trajectories of Big Five Personality Traits: A Coordinated Analysis of 16 Longitudinal Samples
This study assessed change in selfâreported Big Five personality traits. We conducted a coordinated integrative data analysis using data from 16 longitudinal samples, comprising a total sample of over 60 000 participants. We coordinated models across multiple datasets and fit identical multiâlevel growth models to assess and compare the extent of trait change over time. Quadratic change was assessed in a subset of samples with four or more measurement occasions. Across studies, the linear trajectory models revealed declines in conscientiousness, extraversion, and openness. Nonâlinear models suggested lateâlife increases in neuroticism. Metaâanalytic summaries indicated that the fixed effects of personality change are somewhat heterogeneous and that the variability in trait change is partially explained by sample age, country of origin, and personality measurement method. We also found mixed evidence for predictors of change, specifically for sex and baseline age. This study demonstrates the importance of coordinated conceptual replications for accelerating the accumulation of robust and reliable findings in the lifespan developmental psychological sciences. © 2020 European Association of Personality PsychologyPeer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/1/per2259.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/2/per2259-sup-0001-Data_S1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/3/per2259-sup-0002-Open_Practices_Disclosure_Form.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/156004/4/per2259_am.pd
Is healthy neuroticism associated with health behaviors? A coordinated integrative data analysis
Current literature suggests that neuroticism is positively associated with maladaptive life choices, likelihood of disease, and mortality. However, recent research has identified circumstances under which neuroticism is associated with positive outcomes. The current project examined whether âhealthy neuroticismâ, defined as the interaction of neuroticism and conscientiousness, was associated with the following health behaviors: smoking, alcohol consumption, and physical activity. Using a pre-registered multi-study coordinated integrative data analysis (IDA) approach, we investigated whether âhealthy neuroticismâ predicted the odds of engaging in each of the aforementioned activities. Each study estimated identical models, using the same covariates and data transformations, enabling optimal comparability of results. These results were then meta-analyzed in order to estimate an average (N-weighted) effect and to ascertain the extent of heterogeneity in the effects. Overall, these results suggest that neuroticism alone was not related to health behaviors, while individuals higher in conscientiousness were less likely to be smokers or drinkers, and more likely to engage in physical activity. In terms of the healthy neuroticism interaction of neuroticism and conscientiousness, significant interactions for smoking and physical activity suggest that the association between neuroticism and health behaviors was smaller among those high in conscientiousness. These findings lend credence to the idea that healthy neuroticism may be linked to certain health behaviors and that these effects are generalizable across several heterogeneous samples
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