Macrophages promote epithelial proliferation following infectious and non-infectious lung injury through a Trefoil factor 2-dependent mechanism.

Coordinated efforts between macrophages and epithelia are considered essential for wound healing, but the macrophage-derived molecules responsible for repair are poorly defined. This work demonstrates that lung macrophages rely upon Trefoil factor 2 to promote epithelial proliferation following damage caused by sterile wounding, Nippostrongylus brasiliensis or Bleomycin sulfate. Unexpectedly, the presence of T, B, or ILC populations was not essential for macrophage-driven repair. Instead, conditional deletion of TFF2 in myeloid-restricted CD11cCre TFF2 flox mice exacerbated lung pathology and reduced the proliferative expansion of CD45- EpCAM+ pro-SPC+ alveolar type 2 cells. TFF2 deficient macrophages had reduced expression of the Wnt genes Wnt4 and Wnt16 and reconstitution of hookworm-infected CD11cCre TFF2flox mice with rWnt4 and rWnt16 restored the proliferative defect in lung epithelia post-injury. These data reveal a previously unrecognized mechanism wherein lung myeloid phagocytes utilize a TFF2/Wnt axis as a mechanism that drives epithelial proliferation following lung injury

Temporal behavior of resonant‐optical‐waveguide phase‐locked diode laser arrays

Measurements of the temporal and spatial behavior of resonant optical waveguide (ROW) laser arrays with significant interelement loss reveal the presence of sustained self‐pulsations in the output intensity of the laser. The mechanism responsible for pulsations is believed to be saturable absorption arising from the presence of absorbers in the interelement regions. This is experimentally confirmed in that reduction or elimination of the interelement loss suppresses the pulsations. Quiescent behavior is obtained to at least 0.45 W continuous wave power and 3.4 times threshold in near‐diffraction‐limited beams from devices with negligible interelement loss.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70212/2/APPLAB-64-7-827-1.pd

Leveraging Rationales to Improve Human Task Performance

Machine learning (ML) systems across many application areas are increasingly demonstrating performance that is beyond that of humans. In response to the proliferation of such models, the field of Explainable AI (XAI) has sought to develop techniques that enhance the transparency and interpretability of machine learning methods. In this work, we consider a question not previously explored within the XAI and ML communities: Given a computational system whose performance exceeds that of its human user, can explainable AI capabilities be leveraged to improve the performance of the human? We study this question in the context of the game of Chess, for which computational game engines that surpass the performance of the average player are widely available. We introduce the Rationale-Generating Algorithm, an automated technique for generating rationales for utility-based computational methods, which we evaluate with a multi-day user study against two baselines. The results show that our approach produces rationales that lead to statistically significant improvement in human task performance, demonstrating that rationales automatically generated from an AI's internal task model can be used not only to explain what the system is doing, but also to instruct the user and ultimately improve their task performance.Comment: ACM IUI 202

Structural Characterization of a High-Temperature, Ionic Conducting Ceramic using Perturbed Angular Correlation Spectroscopy

Perturbed angular correlation (PAC) spectroscopy has been used to characterize several structural aspects of a high-temperature, ionic conducting ceramic, CaZr3.95Hf0.05P6O24. Hafnium was introduced into the material to provide the PAC probe nuclei, 181Hf/181Ta, which were located primarily at Zr sites. PAC measurements were made over a range of temperatures from 77 to 1180 K, and they have been analyzed and interpreted using several simple models. The distorted octahedral crystal field at the Zr site produced a (low-frequency) static electric quadrupole interaction which can be accurately described by the point-charge model. But, the temperature dependence of the associated electric field gradient (EFG) cannot be described accurately by purely static considerations via the point-charge model and high-temperature x-ray diffraction data. Although a high-frequency static interaction was also observed, the measurements were not sufficiently accurate to identify its origin unambiguously. Some of the high-temperature measurements show evidence of a time-varying interaction, which may result from Ca2+-ion jumping. But, jump frequencies derived classically from high-temperature electrical dc conductivity measurements are too low to agree with those indicated by the PAC data. However, the dc conductivity measurements support a simple model of thermally activated Ca2+-ion transport. The temperature dependence of the EFG (corresponding to the low-frequency interaction) was used to determine an effective Debye-Waller factor. As a result of using this approach to analyze this type of PAC data, this factor was shown also to agree qualitatively with the predictions of the Debye crystal model, although significant theoretical limitations were encountered. These particular results suggest that the PAC technique may provide new insights into understanding advanced ceramic materials

Universal Distributions for Growth Processes in 1+1 Dimensions and Random Matrices

We develop a scaling theory for KPZ growth in one dimension by a detailed study of the polynuclear growth (PNG) model. In particular, we identify three universal distributions for shape fluctuations and their dependence on the macroscopic shape. These distribution functions are computed using the partition function of Gaussian random matrices in a cosine potential.Comment: 4 pages, 3 figures, 1 table, RevTeX, revised version, accepted for publication in PR

Reduction in oxidatively generated DNA damage following smoking cessation

<p>Abstract</p> <p>Background</p> <p>Cigarette smoking is a known cause of cancer, and cancer may be in part due to effects of oxidative stress. However, whether smoking cessation reverses oxidatively induced DNA damage unclear. The current study sought to examine the extent to which three DNA lesions showed significant reductions after participants quit smoking.</p> <p>Methods</p> <p>Participants (n = 19) in this study were recruited from an ongoing 16-week smoking cessation clinical trial and provided blood samples from which leukocyte DNA was extracted and assessed for 3 DNA lesions (thymine glycol modification [d(T^gpA)]; formamide breakdown of pyrimidine bases [d(T^gpA)]; 8-oxo-7,8-dihydroguanine [d(G^h)]) via liquid chromatography tandem mass spectrometry (LC-MS/MS). Change in lesions over time was assessed using generalized estimating equations, controlling for gender, age, and treatment condition.</p> <p>Results</p> <p>Overall time effects for the d(T^gpA) (χ²(3) = 8.068, p < 0.045), d(P^fpA) (χ²(3) = 8.477, p < 0.037), and d(G^h) (χ²(3) = 37.599, p < 0.001) lesions were seen, indicating levels of each decreased significantly after CO-confirmed smoking cessation. The d(T^gpA) and d(P^fpA) lesions show relatively greater rebound at Week 16 compared to the d(G^h) lesion (88% of baseline for d(T^gpA), 64% of baseline for d(P^fpA), vs 46% of baseline for d(G^h)).</p> <p>Conclusions</p> <p>Overall, results from this analysis suggest that cigarette smoking contributes to oxidatively induced DNA damage, and that smoking cessation appears to reduce levels of specific damage markers between 30-50 percent in the short term. Future research may shed light on the broader array of oxidative damage influenced by smoking and over longer durations of abstinence, to provide further insights into mechanisms underlying carcinogenesis.</p