Time-Resolved Ultrafast Transient Polarization Spectroscopy to Investigate Nonlinear Processes and Dynamics in Electronically Excited Molecules on the Femtosecond Time Scale

We report a novel experimental technique to investigate ultrafast dynamics in photoexcited molecules by probing the third-order nonlinear optical susceptibility. A non-colinear 3-pulse scheme is developed to probe the ultrafast dynamics of excited electronic states using the optical Kerr effect by time-resolved polarization spectroscopy. Optical heterodyne and optical homodyne detection are demonstrated to measure the third-order nonlinear optical response for the S1 excited state of liquid nitrobenzene, which is populated by 2-photon absorption of a 780 nm 35 fs excitation pulse.Comment: 12 pages, 4 figures. Changes from previous version: added panel labels to figures 3-

Visualizing Software Architecture Evolution Using Change-Sets

When trying to understand the evolution of a software system it can be useful to visualize the evolution of the sys-tem’s architecture. Existing tools for viewing architectural evolution assume that what a user is interested in can be described in an unbroken sequence of time, for example the changes over the last six months. We present an alternative approach that provides a lightweight method for examining the net effect of any set of changes on a system’s architec-ture. We also present Motive, a prototype tool that imple-ments this approach, and demonstrate how it can be used to answer questions about software evolution by describing case studies we conducted on two Java systems.

Psychosocial Adjustment, Health-Related Quality of Life, and Psychosexual Development of Boys with Hypospadias: A Systematic Review

Objective A systematic review of studies on psychosocial adjustment, HRQoL (health-related quality of life), and psychosexual development of boys with hypospadias. Methods Research was conducted on several online bibliographic databases. Articles were selected on the basis of predefined criteria. Methodological quality was assessed by two independent reviewers who applied a standardized checklist. When possible, data analyses were performed by calculating effect sizes. Results Thirteen studies met the criteria for inclusion, whose methodological standard ranged from low to high quality. None of them has focused on HRQoL. Findings with regard to psychosocial and psychosexual adjustment were inconsistent, though they clearly showed that boys with hypospadias suffer from negative genital appraisal and sexual inhibitions. Overall, medical factors exerted a rather small influence. Psychosocial risk factors have hardly been examined so far. Conclusions The identification of psychosocial risk factors in methodologically sound studies is necessary to guarantee a comprehensive treatment for boys with hypospadia

Chiral 1D Floquet topological insulators beyond rotating wave approximation

We study one-dimensional (1D) Floquet topological insulators with chiral symmetry going beyond the standard rotating wave approximation. The occurrence of many anticrossings between Floquet replicas leads to a dramatic extension of phase diagram regions with stable topological edge states (TESs). We present an explicit construction of all TESs in terms of a truncated Floquet Hamiltonian in frequency space, prove the bulk-boundary correspondence, and analyze the stability of the TESs in terms of their localization lengths. We propose experimental tests of our predictions in curved bilayer graphene.Comment: 4+9 page

Flipping the Classroom to Train Citizen Scientists in Invasive Species Detection and Response

Extension educators are increasingly using flipped classrooms, wherein online content delivery precedes in-person learning. We have applied this approach to two Extension programs in which citizen scientists are trained in early detection of invasive species. Our goal in using the tool of flipped classrooms is to accommodate large amounts of content while focusing classroom time on skills development. In 2017, we assessed efficacy of the flipped classroom through knowledge tests and surveys completed by 174 participants and 106 participants, respectively. Results demonstrated large knowledge gains and high participant satisfaction. We encourage Extension professionals to consider whether use of the flipped classroom format could advance achievement of their programs\u27 learning objectives

Ultrafast Dynamics of Excited Electronic States in Nitrobenzene Measured by Ultrafast Transient Polarization Spectroscopy.

We investigate ultrafast dynamics of the lowest singlet excited electronic state in liquid nitrobenzene using ultrafast transient polarization spectroscopy, extending the well-known technique of optical Kerr effect spectroscopy to excited electronic states. The third-order nonlinear response of the excited molecular ensemble is measured using a pair of femtosecond pulses following a third femtosecond pulse that populates the S1 excited state. By measuring this response, which is highly sensitive to details of the excited state character and structure, as a function of time delays between the three pulses involved, we extract the dephasing time of the wave packet on the excited state. The dephasing time, measured as a function of time delay after pump excitation, shows oscillations indicating oscillatory wave packet dynamics on the excited state. From the experimental measurements and supporting theoretical calculations, we deduce that the wave packet completely leaves the S1 state potential energy surface after three traversals of the intersystem crossing between the singlet S1 and triplet T2 states

Laparoscopic Ureteroureterostomy vs. Common Sheath Ureteral Reimplantation in Children With Duplex Kidney Anomalies

Purpose: Laparoscopic ureteroureterostomy (LUU) has been proposed as an alternative to common sheath ureteral reimplantation (CSUR) in children with symptomatic duplex kidneys. However, data is limited for LUU in the pediatric population. The aim of this study was to analyze our experience with LUU and to compare the results with those after CSUR to assess whether a less invasive surgical approach could be a valid alternative. Patients and methods: The data of all children with duplex kidneys who underwent either LUU or CSUR at our center from 2006 to 2018 were reviewed retrospectively. After parental counseling, the option of LUU was provided as an alternative to CSUR for unilateral procedures and in the absence of vesicoureteral reflux to the receiving ureter. Baseline characteristics, indication for surgery, hospitalization and operative times, and intraoperative, post-operative, and late complications were analyzed. Preoperative and 1-year post-operative sonographies were reviewed by a pediatric radiologist. Increasing renal pelvic diameter (Δ >5 mm) was regarded as a sign of ureteral obstruction. Results: Forty children were included in this study, with 16 children receiving LUU and 24 children receiving CSUR. The children had a mean age of 2.7 years (7 months-9.8 years) and were followed up in our outpatient clinic for an average of 3.9 years (3 months-10.6 years) after surgery. The median hospital stay was 2 days shorter after LUU. Initially, a considerably longer time was needed for LUU, but after more experience was gained, similar operative times were observed for both procedures. Complications were encountered in both groups. After LUU, two patients developed anastomotic leakage: one was managed conservatively, and one required temporary nephrostomy. In the CSUR group, one patient developed vesicoureteral obstruction during follow-up and required reoperation with LUU. The occurrence of post-operative urinary tract infections was similar in both groups. No complications related to the ureteral stump after LUU arose. Conclusion: LUU is a safe and efficacious treatment option for children with duplex kidney anomalies and can be used as an alternative to CSUR. All children receiving LUU showed a non-obstructive, patent anastomosis and no signs for stenotic compromise of the receiving ureter

Development and Characterization of an Enzymatic Method for the Rapid Determination of Gamma Hydroxybutyric Acid

Gamma hydroxybutyric acid (GHB) is a regulated therapeutic drug, which naturally occurs in mammalian brain tissues as an intermediate of the GABA (gamma aminobutyric acid) neurotransmitter metabolism. The increasing misuse of GHB as a narcotic or abusing drug in recent years calls for the development of a simple and rapid screening method as an alternative to the currently available, technically demanding diagnostic methods. We have developed a rapid enzymatic assay based on the GHB dehydrogenase of Ralstonia eutropha. The enzyme is expressed as a recombinant protein in Escherichia coli and characterized in terms of reaction mechanism and kinetic parameters for the catalysis of conversion of GHB into succinic semialdehyde (SSA). The concomitant NADH production enables spectrophotometric monitoring of the reaction and the quantification of GHB in physiological fluids depending on initial velocities. We have tested a panel of twelve serum and urine samples containing GHB concentrations from 0.0 to 2.1 mmol/L. GHB dehydrogenase activity obeys a non classical bi bi ping pong mechanism exhibiting substrate inhibition by NAD+. With an optimal NAD+ concentration of 3.7 mmol/L in the reaction, the enzyme yields a KM of 1.0 mmol/L for GHB and a Vmax of 3.37 mmol/min/mg. The assay shows a linear standard curve from 0.1 to at least 1 mmol/L of GHB. Spiking experiments result in mean recoveries of 92% for urine and 114% for serum, respectively. The comparison to an ion chromatographic reference method exhibits a mean difference of 10% divergence from the target values in urine and 9% in serum, respectively

Chromosome-Level Genome Assembly for the Angiosperm Silene conica.

The angiosperm genus Silene has been the subject of extensive study in the field of ecology and evolution, but the availability of high-quality reference genome sequences has been limited for this group. Here, we report a chromosome-level assembly for the genome of Silene conica based on Pacific Bioscience HiFi, Hi-C, and Bionano technologies. The assembly produced 10 scaffolds (1 per chromosome) with a total length of 862 Mb and only ∼1% gap content. These results confirm previous observations that S. conica and its relatives have a reduced base chromosome number relative to the genus\u27s ancestral state of 12. Silene conica has an exceptionally large mitochondrial genome (\u3e11 Mb), predominantly consisting of sequence of unknown origins. Analysis of shared sequence content suggests that it is unlikely that transfer of nuclear DNA is the primary driver of this mitochondrial genome expansion. More generally, this assembly should provide a valuable resource for future genomic studies in Silene, including comparative analyses with related species that recently evolved sex chromosomes