Ptychographic ultrafast pulse reconstruction

We demonstrate a new ultrafast pulse reconstruction modality which is somewhat reminiscent of frequency resolved optical gating but uses a modified setup and a conceptually different reconstruction algorithm that is derived from ptychography. Even though it is a second order correlation scheme it shows no time ambiguity. Moreover, the number of spectra to record is considerably smaller than in most other related schemes which, together with a robust algorithm, leads to extremely fast convergence of the reconstruction.Comment: 4 pages, 4 figures, 3 references added, new figure 2, matches published versio

Which is more cost‐effective under the MELD system: primary liver transplantation, or salvage transplantation after hepatic resection or after loco‐regional therapy for hepatocellular carcinoma within Milan criteria?

AbstractObjectiveThe optimal strategy for treating hepatocellular carcinoma (HCC), a disease with increasing incidence, in patients with Child–Pugh class A cirrhosis has long been debated. This study evaluated the cost‐effectiveness of hepatic resection (HR) or locoregional therapy (LRT) followed by salvage orthotopic liver transplantation (SOLT) vs. that of primary orthotopic liver transplantation (POLT) for HCC within the Milan Criteria.MethodsA Markov‐based decision analytic model simulated outcomes, expressed in costs and quality‐adjusted life years (QALYs), for the three treatment strategies. Baseline parameters were determined from a literature review. Sensitivity analyses tested model strength and parameter variability.ResultsBoth HR and LRT followed by SOLT were associated with earlier recurrence, decreased survival, increased costs and decreased quality of life (QoL), whereas POLT resulted in decreased recurrence, increased survival, decreased costs and increased QoL. Specifically, HR/SOLT yielded 3.1QALYs (at US$96000/QALY) and LRT/SOLT yielded 3.9QALYs (at US$74000/QALY), whereas POLT yielded 5.5QALYs (at US$52000/QALY). Sensitivity analyses supported these findings at clinically meaningful probabilities.ConclusionsUnder the Model for End‐stage Liver Disease (MELD) system, in patients with HCC within the Milan Criteria, POLT increases survival and QoL at decreased costs compared with HR or LRT followed by SOLT. Therefore, POLT is the most cost‐effective strategy for the treatment of HCC

Synchrony of physiological activity during mother-child interaction: moderation by maternal history of major depressive disorder

The family environment plays an important role in the intergenerational transmission of MDD, but less is known about how day-to-day mother-child interactions may be disrupted in families with a history of MDD. Disruptions in mother-child synchrony, the dynamic and convergent exchange of physiological and behavioral cues during interactions, may be one important risk factor. Although maternal MDD is associated with a lack of mother-child synchrony at the behavioral level, no studies have examined the impact of maternal MDD on physiological synchrony. Therefore, the current study examined whether maternal history of MDD moderates mother-child physiological synchrony (measured via RSA) during positive and negative discussions

Is liver transplantation using organs donated after cardiac death cost‐effective or does it decrease waitlist death by increasing recipient death?

AbstractObjectivesThe aim of this study was to evaluate the cost‐effectiveness in liver transplantation (LT) of utilizing organs donated after cardiac death (DCD) compared with organs donated after brain death (DBD).MethodsA Markov‐based decision analytic model was created to compare two LT waitlist strategies distinguished by organ type: (i) DBD organs only, and (ii) DBD and DCD organs. The model simulated outcomes for patients over 10 years with annual cycles through one of four health states: survival; ischaemic cholangiopathy; retransplantation, and death. Baseline values and ranges were determined from an extensive literature review. Sensitivity analyses tested model strength and parameter variability.ResultsOverall survival is decreased, and biliary complications and retransplantation are increased in recipients of DCD livers. Recipients of DBD livers gained 5.6 quality‐adjusted life years (QALYs) at a cost of US$69 000/QALY, whereas recipients on the DBD + DCD LT waitlist gained 6.0 QALYs at a cost of US$61 000/QALY. The DBD + DCD organ strategy was superior to the DBD organ‐only strategy.conclusionsThe extension of life and quality of life provided by DCD LT to patients on the waiting list who might otherwise not receive a liver transplant makes the continued use of DCD livers cost‐effective

Which is more cost‐effective under the MELD system: primary liver transplantation, or salvage transplantation after hepatic resection or after loco‐regional therapy for hepatocellular carcinoma within Milan criteria?

AbstractObjectiveThe optimal strategy for treating hepatocellular carcinoma (HCC), a disease with increasing incidence, in patients with Child–Pugh class A cirrhosis has long been debated. This study evaluated the cost‐effectiveness of hepatic resection (HR) or locoregional therapy (LRT) followed by salvage orthotopic liver transplantation (SOLT) vs. that of primary orthotopic liver transplantation (POLT) for HCC within the Milan Criteria.MethodsA Markov‐based decision analytic model simulated outcomes, expressed in costs and quality‐adjusted life years (QALYs), for the three treatment strategies. Baseline parameters were determined from a literature review. Sensitivity analyses tested model strength and parameter variability.ResultsBoth HR and LRT followed by SOLT were associated with earlier recurrence, decreased survival, increased costs and decreased quality of life (QoL), whereas POLT resulted in decreased recurrence, increased survival, decreased costs and increased QoL. Specifically, HR/SOLT yielded 3.1QALYs (at US$96000/QALY) and LRT/SOLT yielded 3.9QALYs (at US$74000/QALY), whereas POLT yielded 5.5QALYs (at US$52000/QALY). Sensitivity analyses supported these findings at clinically meaningful probabilities.ConclusionsUnder the Model for End‐stage Liver Disease (MELD) system, in patients with HCC within the Milan Criteria, POLT increases survival and QoL at decreased costs compared with HR or LRT followed by SOLT. Therefore, POLT is the most cost‐effective strategy for the treatment of HCC

Hyperparameter Importance Across Datasets

With the advent of automated machine learning, automated hyperparameter optimization methods are by now routinely used in data mining. However, this progress is not yet matched by equal progress on automatic analyses that yield information beyond performance-optimizing hyperparameter settings. In this work, we aim to answer the following two questions: Given an algorithm, what are generally its most important hyperparameters, and what are typically good values for these? We present methodology and a framework to answer these questions based on meta-learning across many datasets. We apply this methodology using the experimental meta-data available on OpenML to determine the most important hyperparameters of support vector machines, random forests and Adaboost, and to infer priors for all their hyperparameters. The results, obtained fully automatically, provide a quantitative basis to focus efforts in both manual algorithm design and in automated hyperparameter optimization. The conducted experiments confirm that the hyperparameters selected by the proposed method are indeed the most important ones and that the obtained priors also lead to statistically significant improvements in hyperparameter optimization.Comment: \c{opyright} 2018. Copyright is held by the owner/author(s). Publication rights licensed to ACM. This is the author's version of the work. It is posted here for your personal use, not for redistribution. The definitive Version of Record was published in Proceedings of the 24th ACM SIGKDD International Conference on Knowledge Discovery & Data Minin

Anti-Kasha Conformational Photoisomerization of a Heteroleptic Dithiolene Metal Complex Revealed by Ultrafast Spectroscopy

We investigated the anti-Kasha photochemistry and anti-Kasha emission of d8-metal donor-acceptor dithiolene with femtosecond UV-vis transient absorption spectroscopy and molecular modeling. Experimentally, we found a lifetime of 1.4 ps for higher excited states, which is exceptionally long when compared to typical values for internal conversion (IC) (10 s of fs or less). Consequently, a substantial emission originates from the second excited state. Molecular modeling suggests this to be a consequence of the spatially separated molecular orbitals of the first and second excited states, which gives a charge transfer character to the IC. More surprisingly, we found that the inherent flexibility of the molecule allows the metal complex to access different configurations depending on the photoexcited state. We believe that this unique manifestation of anti-Kasha photoinduced conformational isomerization is facilitated by the exceptionally long lifetime of the second excited state

BlinkML: Efficient Maximum Likelihood Estimation with Probabilistic Guarantees

The rising volume of datasets has made training machine learning (ML) models a major computational cost in the enterprise. Given the iterative nature of model and parameter tuning, many analysts use a small sample of their entire data during their initial stage of analysis to make quick decisions (e.g., what features or hyperparameters to use) and use the entire dataset only in later stages (i.e., when they have converged to a specific model). This sampling, however, is performed in an ad-hoc fashion. Most practitioners cannot precisely capture the effect of sampling on the quality of their model, and eventually on their decision-making process during the tuning phase. Moreover, without systematic support for sampling operators, many optimizations and reuse opportunities are lost. In this paper, we introduce BlinkML, a system for fast, quality-guaranteed ML training. BlinkML allows users to make error-computation tradeoffs: instead of training a model on their full data (i.e., full model), BlinkML can quickly train an approximate model with quality guarantees using a sample. The quality guarantees ensure that, with high probability, the approximate model makes the same predictions as the full model. BlinkML currently supports any ML model that relies on maximum likelihood estimation (MLE), which includes Generalized Linear Models (e.g., linear regression, logistic regression, max entropy classifier, Poisson regression) as well as PPCA (Probabilistic Principal Component Analysis). Our experiments show that BlinkML can speed up the training of large-scale ML tasks by 6.26x-629x while guaranteeing the same predictions, with 95% probability, as the full model.Comment: 22 pages, SIGMOD 201

Ground deformation detection of the greater area of Thessaloniki (Northern Greece) using radar interferometry techniques

In the present study SAR interferometric techniques (stacking of conventional interferograms and Permanent Scatterers), using images from satellites ERS-1 and 2, have been applied to the region of Thessaloniki (northern Greece). The period covered by the images is 1992–2000. Both techniques gave good quantitative and qualitative results. The interferometric products were used to study ground surface deformation phenomena that could be related to the local tectonic context, the exploitation of underground water and sediments compaction. <br><br> The city of Thessaloniki shows relatively stable ground conditions. Subsidence in four locations, mainly in the area surrounding the city of Thessaloniki, has been detected and assessed. Two of the sites (Sindos-Kalochori and Langadhas) were already known from previous studies as subsiding areas, using ground base measurements. On the contrary the other two sites in the northern suburbs of Thessaloniki (Oreokastro) and in the south-east (airport area) were unknown as areas of subsidence. A further investigation based on fieldwork is needed in these two areas. Finally, an attempt to interpret the observed deformation, according to the geological regime of the area and its anthropogenic activities, has been carried out