The D-bar Method for Diffuse Optical Tomography: a computational study

The D-bar method at negative energy is numerically implemented. Using the method we are able to numerically reconstruct potentials and investigate exceptional points at negative energy. Subsequently, applying the method to Diffusive Optical Tomography, a new way of reconstructing the diffusion coefficient from the associated Complex Geometrics Optics solution is suggested and numerically validated

The D-Bar Method for Diffuse Optical Tomography : A Computational Study

The D-bar method at negative energy is numerically implemented. Using the method, we are able to numerically reconstruct potentials and investigate exceptional points at negative energy. Subsequently, applying the method to diffuse optical tomography, a new way of reconstructing the diffusion coefficient from the associated Complex Geometrics Optics solution is suggested and numerically validated.Peer reviewe

The impact of sleep on eyewitness identifications

Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.Peer reviewe

Experimental evaluation of nutrient limitation of phytoplankton communities in the Gulf of Riga

http://www.elsevier.com/locate/issn/09247963Phytoplankton nutrient limitation was studied in the Gulf of Riga during spring bloom April 1995., early summer stage June 1994., cyanobacterial bloom July 1994. and post cyanobacterial bloom August 1993.. Each year six factorial nutrient enrichment experiments were carried out in various locations in the Gulf; including outer Irbe Strait, northern Gulf and southern Gulf. The responses of natural phytoplankton communities to the nutrient additions 80 mg NH4-N ly1, 20 mg PO4-P ly1 and two levels of combined additions. were followed for 3 days using 6 l experimental units. To evaluate the nutrient limitation patterns, time series of chlorophyll a were analysed using polynomial regression models and ranking method, taking advantage of the relatively constant experimental error. Apparent nutrient depletion rates and ratios were estimated, and compared with the changes in particulate nutrient ratios. During the spring diatom bloom in 1995, ambient inorganic nutrient concentrations were still high, and thus phytoplankton biomass did not respond to additions of nutrients. Chlorophyll a specific nutrient depletion rates were low 0.01-0.12 mg Nmg chl a.y1 hy1 and 0.002-0.016 mg P mg chl a.y1 hy1. and linear over time, thus also revealing that phytoplankton was not limited by these nutrients in that time. In June 1994, there was an areal shift from N limitation in the outer Irbe Strait towards co-limitation in the southern Gulf. Later in July 1994, during the bloom of N-fixing Aphanizomenon flos-aquae, the N limitation was obvious for the whole study area. For this period chlorophyll a specific nutrient depletion rates were high 0.360.67 mg N mg chl a.y1 hy1 and 0.089-0.135 mg Pmg chl a.y1 hy1., and added nutrients were almost totally depleted during the first light period. After the collapse of cyanobacterial bloom in August 1993, the experiment carried out in the southern Gulf indicated P limitation of phytoplankton. The central Gulf was obviously co-limited, while the area between northern Gulf and outer Irbe Strait was N-limited. Our results indicate that phytoplankton in the Gulf of Riga, earlier considered strictly as P-limited, is at least until late-summer period N- or co-limited. It seems also obvious that there exists a spatial tendency in the phytoplankton limitation patterns, generally from more P- or co-limited southern Gulf towards more N-limited northern basin

Random forest machine learning method outperforms prehospital National Early Warning Score for predicting one-day mortality : A retrospective study

Aim of the study: The National Early Warning Score (NEWS) is a validated method for predicting clinical deterioration in hospital wards, but its performance in prehospital settings remains controversial. Modern machine learning models may outperform traditional statistical analyses for predicting short-term mortality. Thus, we aimed to compare the mortality prediction accuracy of NEWS and random forest machine learning using prehospital vital signs. Methods: In this retrospective study, all electronic ambulance mission reports between 2008 and 2015 in a single EMS system were collected. Adult patients (>= 18 years) were included in the analysis. Random forest models with and without blood glucose were compared to the traditional NEWS for predicting one-day mortality. A ten-fold cross-validation method was applied to train and validate the random forest models. Results: A total of 26,458 patients were included in the study of whom 278 (1.0%) died within one day of ambulance mission. The area under the receiver operating characteristic curve for one-day mortality was 0.836 (95% CI, 0.810-0.860) for NEWS, 0.858 (95% CI, 0.832-0.883) for a random forest trained with NEWS variables only and 0.868 (0.843-0.892) for a random forest trained with NEWS variables and blood glucose. Conclusion: A random forest algorithm trained with NEWS variables was superior to traditional NEWS for predicting one-day mortality in adult prehospital patients, although the risk of selection bias must be acknowledged. The inclusion of blood glucose in the model further improved its predictive performance.Peer reviewe

Biliary Anomalies in Patients With HNF1B Diabetes

Context: The clinical spectrum of organogenetic anomalies associated with HNF1B mutations is heterogeneous. Besides cystic kidney disease, diabetes, and various other manifestations, odd cases of mainly neonatal and posttransplantation cholestasis have been described. The biliary phenotype is incompletely defined. Objective: To systematically characterize HNF1B-related anomalies in the bile ducts by imaging with magnetic resonance imaging (MRI) or magnetic resonance cholangiopancreatography (MRCP). Setting and Patients: Fourteen patients with HNF1B mutations in the catchment area of the Helsinki University Hospital were evaluated with upper abdominal MRI and MRCP. Blood samples and clinical history provided supplemental data on the individual phenotype. Main Outcome Measure(s): Structural anomalies in the biliary system, medical history of cholestasis, other findings in abdominal organs, diabetes and antihyperglycemic treatment, hypomagnesemia, and hyperuricemia. Results: Structural anomalies of the bile ducts were found in seven of 14 patients (50%). Six patients had choledochal cysts, which are generally considered premalignant. Conclusions: Structural anomalies of the biliary system were common in HNF1B mutation carriers. The malignant potential of HNF1B-associated choledochal cysts warrants further studies.Peer reviewe

Forest soil carbon stock estimates in a nationwide inventory: evaluating performance of the ROMULv and Yasso07 models in Finland

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Exploring the error characteristics of thin ice cloud property retrievals using a Markov chain Monte Carlo algorithm

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95385/1/jgrd15111.pd