bluuebunny/crossref_metadata_2025 huggingface dataset:
Apathy in idiopathic normal pressure hydrocephalus: A marker of reversible gait disorders
Authors: Allali Gilles , Laidet Magali , Armand Stéphane , Saj Arnaud , Krack Paul , Assal Frédéric
Published: January 2018

Objective

Apathy—the most common behavioral disturbance in idiopathic normal pressure hydrocephalus (iNPH)—is associated with poor gait, but the role of apathy on gait improvement after cerebrospinal fluid (CSF) tapping has not been studied yet. This study aims to compare gait improvement after CSF tapping in iNPH patients with and without apathy.

Methods

Stride time variability (STV), a marker of higher level of gait control, was measured in 33 iNPH patients (78.4 ± 5.7 years; 36.4% women) with an optoelectronic system during usual walking (single task) and during walking while dual tasking of counting and verbal fluency before and 24 hours after CSF tapping. Apathy was defined by a score ≥14 on the Starkstein apathy scale.

Results

Apathy was present in 60.6% of patients. Cerebrospinal fluid tapping led to greater improvement of STV (ie, decrease) during dual‐task walking (and more specifically categorical verbal fluency) in apathetic compared to nonapathetic patients (−44.7 ± 58.1% versus +4.24 ± 67.6%, respectively; P = .040), even after adjusting for age and depressive symptoms. More severe apathy was correlated with better STV improvement while dual tasking (categorical verbal fluency) after CSF tapping (r = −0.412; P‐value = 0.021), while it was not correlated with improvement on executive tests.

Conclusions

Our findings suggest that the presence of apathy is a predictor of better outcomes of gait disorders after CSF tapping in patients with iNPH.
HMGB1‐induced asthmatic airway inflammation through GRP75‐mediated enhancement of ER‐mitochondrial Ca2+ transfer and ROS increased
Authors: Lv Yanhua , Li Yanli , Zhang Dandan , Zhang Anbing , Guo Weihong , Zhu Shunfang
Published: January 2018

Imbalanced T‐helper (TH)1/Th2 response contributes significantly to asthma pathogenesis. Our study indicated that HMGB1 play an important role in the release of Th2‐associated cytokines of asthma. However, the specific mechanism about HMGB1‐induced imbalanced TH1/Th2 response is not known. In vivo, an OVA‐induced asthma mouse model was set up and mice treated with anti‐HMGB1 IgG. The mice treated with the anti‐HMGB1 IgG ameliorated airway hyper‐reactivity, disruption of Th1/Th2 balance and the upregulation of GRP75 induced by OVA. In vitro, the exposure of normal human bronchial epithelial cells to HMGB1 resulted in the upregulation of GRP75, proinflammatory cytokine production, enhanced ER‐Mitochondrial Ca2+ transfer, and enhancement of reactive oxygen species (ROS). While HMGB1‐induced these changes were attenuated by GRP75 siRNA treatment. Sequentially, pretreatment with 2‐APB, SKF960365 (SKF) and Ru360 which inhibit ER‐Mitochondrial Ca2+ transfer significantly lowered HMGB1‐induced the generation of ROS and the release of Th2 cytokines in 16HBE cells. Meanwhile, N‐acetylcysteine (NAC) significantly attenuated the HMGB1‐mediated pro‐inflammatory cytokines release. Therefore, these results indicate that GRP75‐mediated ER‐Mitochondrial Ca2+ transfer may be an important contributor in imbalanced of Th1/Th2 balance of asthma. Moreover, HMGB1 specifically induces the release of Th2 cytokines through GRP75‐mediated enhancement of ER‐Mitochondrial Ca2+ transfer and ROS increased.
Multiple schedules, off‐baseline reinforcement shifts, and resistance to extinction
Authors: Craig Andrew R. , Shahan Timothy A.
Published: January 2018

Resistance to extinction in a target multiple‐schedule component varies inversely with the rate of reinforcement arranged in an alternative component during baseline. The present experiment asked whether changing the reinforcer rate in an alternative component would impact extinction of target component responding if those changes occurred in an off‐baseline phase during which the target component was never experienced. Pigeons' key pecking was studied in three types of conditions, and each condition consisted of three phases. In Phase 1, pecking produced food in the target and alternative components of a multiple schedule according to variable‐interval 60‐s schedules. In Phase 2, the alternative‐component stimulus was presented alone in a single schedule. Pecking during this phase produced the same reinforcer rate as in baseline in the Control condition, a higher rate of food (variable‐interval 15 s) in the High‐Rate condition, or was extinguished in the Extinction condition. Extinction of target‐ and alternative‐component key pecking then was assessed in a multiple schedule during the final phase of each condition. Resistance to extinction of target‐component key pecking was the same between the Control and High‐Rate conditions but lower in the Extinction condition. These findings are discussed in terms of discrimination and generalization processes.
One‐pot Three‐component Route for the Synthesis of Functionalized 4H‐chromenes Catalyzed by ZrOCl2·8H2O in Water
Authors: Halimehjani Azim Ziyaei , Keshavarzi Nahid
Published: January 2018

An efficient method for the synthesis of functionalized 4H‐chromenes via a one‐pot three‐component condensation reaction of a 2‐hydroxybenzaldehyde with an active methylene compound and a carbon‐based nucleophile in the presence of a catalytic amount of ZrOCl2·8H2O in water under thermal condition has been described. High yields, simple work‐up procedure, performing reactions in water and synthesis of complex molecules with a one‐pot procedure are the main advantages of this procedure. In addition, the structure of the product from the condensation of salicylaldehyde, 2‐naphthol, and dimedone was confirmed by X‐ray crystallography.
Intra‐annual variability of heat wave episodes over the east coast of India
Authors: Sandeep A. , Prasad V. S.
Published: January 2018

India is very prone to heat waves during April–June. The intra‐annual variability of heat wave episodes over the east coast of India has been studied using 16‐year NCMRWF global forecast system (NGFS) retrospective data. The objective of this study is threefold: (1) identification of heat wave episodes over the east coast of India, (2) intra‐annual variability of heat wave episodes, and (3) which physical mechanism(s) is responsible for its occurrence and long‐lasting? A total of ten heat wave episodes (100 hot days) were obtained for the period 2000–2015. The intensity of heat wave is found to be maximum (minimum) for 2015 (2007) episode. The average duration of heat wave episodes was 10 days, with the longest episode lasting for 20 days in the year 2003. Moreover, an average duration of severe heat wave is 3.5 days longer than that of a normal heat wave. The common feature observed in all heat wave cases is the presence of anticyclone in the upper troposphere and associated persistence high. This can cause sinking motion, which leads to surface warming due to adiabatic compression. The lack of soil moisture (SM) induces a positive feedback between the surface and the air above it, which amplifies the sensible heating and thereby increases surface temperature. The prevailed westerly anomalies over the study region which reduce the land–sea breeze result in heat wave. The heat wave episodes exhibit a significant intra‐annual variability. Intensity of heat waves averaged over the east coast of India has shown an increase of 0.06 °C per heat wave. The geopotential height anomaly, vertical velocity, and SM exhibit significant intra‐annual variability between the episodes and become decisive parameters for the maintenance and variability. The correlation coefficient between the maximum temperature and SM is found to be −0.56, indicating the importance of SM regulating the intensity of heat waves.
Game Changer in Soil Science. Functional role of clay minerals in soil
Authors: Churchman G. Jock
Published: January 2018

Defining soil clay minerals as all inorganic particles < 2 µm would enhance their predictive power for soil functions. The future task is to unravel the prominent functional role of clay associations in the “ultimate particles” in soils–microaggregates. High energy techniques and decomposition of XRD patterns offer the prospect of understanding associations of silicates, oxides and organic matter within microaggregates.
Development and validation of an analytical method for multiresidue determination of pesticides in lettuce using QuEChERS–UHPLC–MS/MS
Authors: Ribeiro Begnini Konatu Fernanda , Sales Fontes Jardim Isabel Cristina
Published: January 2018

A new analytical method for multiresidue determination of 16 multiclass pesticides in lettuce was developed using ultra‐high performance liquid chromatography with tandem mass spectrometry with a triple quadrupole mass analyzer and positive mode electrospray ionization, using a previously optimized quick, easy, cheap, effective, rugged, and safe method for sample preparation. Validation studies, according to document SANTE/11945/2015, demonstrated that the developed method is selective, accurate, and precise, providing recoveries of 70–120%, relative standard deviations ≤20% and quantification limits from 3 μg/kg. The method was compared with one based on high‐performance liquid chromatography with tandem mass spectrometry, in terms of chromatographic performance, detectability and matrix effect for five varieties of lettuce. The new method provided a reduction in the time for the chromatographic analysis of 50%, from 30 to 15 min, using a lower mobile phase flow rate (0.147 mL/min), which reduced the consumption of mobile phase by 25%, and injection of smaller amounts of sample (1.7 μL). Lower limits of quantification were obtained for almost all pesticides studied for green‐leaf lettuce. However, in relation to the matrix effect, four of the five types of lettuce studied presented higher matrix effects.
Cellulose tris‐(3,5‐dimethylphenylcarbamate)‐based chiral stationary phase for the enantioseparation of drugs in supercritical fluid chromatography: comparison with HPLC
Authors: Kalíková Květa , Martínková Monika , Schmid Martin G. , Tesařová Eva
Published: January 2018

A cellulose tris‐(3,5‐dimethylphenylcarbamate)‐based chiral stationary phase was studied as a tool for the enantioselective separation of 21 selected analytes with different pharmaceutical and physicochemical properties. The enantioseparations were performed using supercritical fluid chromatography. The effect of the mobile phase composition was studied. Four different additives (diethylamine, triethylamine, isopropylamine, and trifluoroacetic acid) and isopropylamine combined with trifluoroacetic acid were tested and their influence on enantioseparation was compared. The influence of two different mobile phase co‐solvents (methanol and propan‐2‐ol) combined with all the additives was also evaluated. The best mobile phase compositions for the separation of the majority of enantiomers were CO2/methanol/isopropylamine 80:20:0.1 v/v/v or CO2/propan‐2‐ol/isopropylamine/trifluoroacetic acid 80:20:0.05:0.05 v/v/v/v. The best results were obtained from the group of basic β‐blockers. A high‐performance liquid chromatography separation system composed of the same stationary phase and mobile phase of similar properties prepared as a mixture of hexane/propan‐2‐ol/additive 80:20:0.1 v/v/v was considered for comparison. Supercritical fluid chromatography was found to yield better results, i.e. better enantioresolution for shorter analysis times than high‐performance liquid chromatography. However, examples of enantiomers better resolved under the optimized conditions in high‐performance liquid chromatography were also found.
Comparison of commercial organic polymer‐based and silica‐based monolithic columns using mixtures of analytes differing in size and chemistry
Authors: Vyviurska Olga , Lv Yongqin , Mann Benjamin F. , Svec Frantisek
Published: January 2018

Commercially available silica‐based monolithic columns Chromolith RP‐8e, Chromolith RP‐18, and Chromolith HR RP‐18, and polymer‐based monolithic columns ProSwift RP‐1S, ProSwift RP‐2H, and ProSwift RP‐3U varying in pore size and bonded phase have been tested for the fast separation of selected sets of analytes. These mixtures of analytes included small molecules (uracil, caffeine, 1‐phenylethanol, butyl paraben, and anthracene), acylated insulins, and intact proteins (ribonuclease A, cytochrome C, transferrin, apomyoglobin, and thyroglobulin), and covered wide range of chemistries and sizes. Small molecules were well separated with a height equivalent to theoretical plate of 11–26 μm using silica‐based monolithic columns, while organic polymer‐based monoliths excelled in the fast sub 1 min baseline separations of large molecules. A peak capacity of 37 was found for separation of acylated insulins on Chromolith columns using a 3 min gradient at a flow rate of 3 ml/min. Poor recovery of proteins from Chromolith columns and significant peak tailing of small molecules using ProSwift columns were the major obstacles in using monolithic columns in those applications.
Effects of environmental factors on soil organic carbon under natural or managed vegetation restoration
Authors: Hu Pei‐Lei , Liu Shu‐Juan , Ye Ying‐Ying , Zhang Wei , Wang Ke‐Lin , Su Yi‐Rong
Published: January 2018

To expand the scientific understanding of soil organic carbon (SOC) accumulation in restored ecosystems, we used 246 soil samples from a rocky catchment (10.24 km2) in an ecologically fragile karst area of southwest China and measured the effects of environmental factors under different vegetation restoration types (managed, including forage grassland and plantation forest, or natural, including grassland, shrubland, and secondary forest) on soil organic carbon content (SOCC) and soil organic carbon density (SOCD). Significantly higher SOCC and SOCD were found in natural vegetation than in managed vegetation and tillage land but no differences in SOCC or SOCD were detected between managed vegetation and tillage land. The environmental factors include rock outcrop ratio (ROR), bulk density, altitude, soil depth, slope gradient, and pH, all showing significant effect on SOC. The proportion of variations in SOCC and SOCD explained by environmental factors was higher in natural vegetation restoration than in managed vegetation restoration, and this proportion increased along the successional gradient. However, the environmental factors driving variations in SOCC and SOCD differed according to vegetation type. Soil bulk density had the strongest effect on SOCC variation in all vegetation types, except for forage grassland, in which the variation was instead controlled by ROR. The variation of SOCD was mainly driven by ROR in most vegetation types, except for tillage land and forage grassland, in which the driving factor was altitude. This results indicated that natural vegetation restoration is more beneficial to SOC sequestration than managed vegetation restoration and thus for mitigating global climate change. Accordingly, future studies should take these different environmental drivers under different vegetation restoration types into consideration when modeling SOC and guiding restoration management.
Tribocorrosion behavior and mechanism of micro‐arc oxidation Ca/P coating on nanocrystallized magnesium alloys
Authors: Yang Jinghua , Gu Yanhong , Zhou Xiaomao , Zhang Yuping
Published: January 2018

In order to improve the corrosion and tribocorrosion resistance of magnesium alloy used as implant materials in human body, a calcium phosphate (Ca/P) containing coating was obtained by micro‐arc oxidation (MAO) on the nano‐layer pretreated by ultrasonic cold forging technology (UCFT). The metallographic structure of the UCFT‐treated sample was observed by metallographic microscope. The thickness of the nanolayer is about 100 µm and the grain size has become smaller than that of the untreated sample. The results show that OCP increases gradually under corrosion and will be up and down under tribocorrosion. PDP data show that the current density of UCFT‐MAO sample is the lowest under corrosion and tribocorrosion, and the current density of the sample under tribocorrosion is higher than that under corrosion. EIS shows that the impedance magnitude (|Z|) of the samples under tribocorrosion is much lower than that of under corrosion. These results indicate that corrosion resistant performance of the UCFT‐MAO sample can be reduced by wear. And a physical model of the tribocorrosion behavior was proposed.
Enhancement of the Insulation Properties of Poly(2‐oxazoline)‐co‐Polyester Networks by the Addition of Nanofillers
Authors: Eibel Alexander , Marx Philipp , Jin Huifei , Tsekmes Ioannis‐Alexandros , Mühlbacher Inge , Smit Johan J. , Kern Wolfgang , Wiesbrock Frank
Published: January 2018

Copoly(2‐nonyl‐2‐oxazoline)‐stat‐poly(2‐dec‐9′enyl‐2‐oxazoline)s can be crosslinked by the thiol‐ene reaction with glycol dimercaptoacetate. The copoly(2‐oxazoline)‐stat‐copolyester is tested as dielectric for high‐voltage applications, either as unfilled resin or as composite with nanoscaled fillers of silica, alumina, and hexagonal boron nitride. During AC voltage tests, all materials have an average breakdown strength of 45–50 kV mm−1. For DC voltage tests, samples with SiO2 (hBN) have an average breakdown strength of ≈100 (80) kV mm−1, while the unfilled copoly(2‐oxazoline) has an average breakdown strength of ≈60 kV mm−1. Permittivity measurements at 20 °C and 50 Hz reveal that all nanocomposites are dielectrics (D = 0.06–0.08), while the unfilled copoly(2‐oxazoline)s has a high loss factor of D = 8.43. This phenomenon can be retraced to the phase separation in the crosslinked copolymer, the M‐OH functionality of silica and alumina particles, and models of polymer–particle interactions such as the Tanaka model, revealing that the nanofillers reduce the interfacial and dipolar polarizability.
Mit Zucker gegen Bösartiges
Authors: Seibel Jürgen , Grimm Clemens , Bechold Julian
Published: January 2018

Eine neue komplexe Zuckerstruktur dockt spezifisch an das Tumorprotein Galektin‐1 an. Als Target sind Galektine schon länger bekannt, nun könnten sie helfen, Krebs zu erkennen.
Lesung, Vorlesung, Namensvorlesung
Authors: Köhler Barbara
Published: January 2018

Die GDCh unterhält mit vielen anderen europäischen chemischen Gesellschaften gemeinsame Vorlesungen, die nach verdienstvollen Chemikern des eigenen und des Nachbarlandes benannt worden sind.
50 Jahre Mitgliedschaft in der CG/GDCh – Wir gratulieren!
Authors: Bräutigam Maximilian , Lindhorst Thisbe K. , Koch Wolfram
Published: January 2018

Zu Beginn des Jahres 2018 gratulieren wir herzlich unseren Kolleginnen und Kollegen zu ihren Goldenen Jubiläen in der GDCh bzw. zu ihren 50‐jährigen Mitgliedschaften in der Chemischen Gesellschaft der DDR (CG) und nach der Wiedervereinigung in der GDCh:
Successful treatment of psychosis in dentatorubral‐pallidoluysian atrophy with quetiapine: A case report
Authors: Narita Zui , Sumiyoshi Tomiki
Published: January 2018

Introduction

Patients with dentatorubral‐pallidoluysian atrophy (DRPLA) sometimes elicit psychosis. First‐generation antipsychotic drugs have been reported to be effective in treating psychotic symptoms associated with the disease. However, little information is available on the benefits of second‐generation antipsychotic drugs (SGAs).

Case

We report on a 47‐year‐old man with DRPLA whose psychotic symptoms were effectively treated with quetiapine, one of the SGAs. He suffered from delusions, auditory hallucinations, and disorganized speech. Initially, other antipsychotic drugs were tried, but were withdrawn because of adverse effects before switching to quetiapine.

Conclusion

Our observations add to the notion that some of the SGAs are useful for ameliorating psychosis in DRPLA.
Validation of an algorithm for identifying type 1 diabetes in adults based on electronic health record data
Authors: Schroeder Emily B. , Donahoo William T. , Goodrich Glenn K. , Raebel Marsha A.
Published: January 2018

Purpose

Algorithms using information from electronic health records to identify adults with type 1 diabetes have not been well studied. Such algorithms would have applications in pharmacoepidemiology, drug safety research, clinical trials, surveillance, and quality improvement. Our main objectives were to determine the positive predictive value for identifying type 1 diabetes in adults using a published algorithm (developed by Klompas et al) and to compare it to a simple requirement that the majority of diabetes diagnosis codes be type 1.

Methods

We applied the Klompas algorithm and the diagnosis code criterion to a cohort of 66 690 adult Kaiser Permanente Colorado members with diabetes. We reviewed 220 charts of those identified as having type 1 diabetes and calculated positive predictive values.

Results

The Klompas algorithm identified 3286 (4.9% of 66 690) adults with diabetes as having type 1 diabetes. Based on chart reviews, the overall positive predictive value was 94.5%. The requirement that the majority of diabetes diagnosis codes be type 1 identified 3000 (4.5%) as having type 1 diabetes and had a positive predictive value of 96.4%. However, the algorithm criterion involving dispensing of urine acetone test strips performed poorly, with a positive predictive value of 20.0%.

Conclusions

Data from electronic health records can be used to accurately identify adults with type 1 diabetes. When identifying adults with type 1 diabetes, we recommend either a modified version of the Klompas algorithm without the urine acetone test strips criterion or the requirement that the majority of diabetes diagnosis codes be type 1 codes.
Dietmar Dath: Dirac
Authors: Heydenreich Aura
Published: January 2018

Physik und Literatur sind symbolische Modi der Welterschließung. Gelingt es, sie kurzzuschließen, entspringen aus diesem Kontakt Funken der Kreativität: neue Möglichkeiten des Erzählens.
Oil in Sicily: Petrocapitalist imaginaries in the shadow of old smokestacks
Authors: Benadusi Mara
Published: January 2018

By describing the long trajectory of petrochemical industrialization in a Mediterranean area in southeastern Sicily locally known as the triangle of death, this article discusses how the widespread, long‐term, and nearly invisible nature of everyday forms of catastrophe generate effects that at times are even more insidious than a major disaster. Indeed, like the fumes rising from an industrial smokestack, oil culture seeps into the imaginaries and epidermises of the people for whom petroleum represents both a blessing and a curse.
“Once you support, you are supported”: Entrepreneurship and reintegration among ex‐prisoners in Gulu, northern Uganda
Authors: Marshall Hannah Jane
Published: January 2018

This article explores the divergences between ex‐prisoners' use of entrepreneurship as a tool for rebuilding social ties and the vision of entrepreneurship provided by Mission Forward, a European‐funded, Ugandan‐run nongovernmental organization that provides ex‐prisoners with entrepreneurship training. Forty‐six interviews were conducted over two months with Mission Forward staff and with ex‐prisoners participating in the entrepreneurship training program in Gulu, northern Uganda. These interviews found that Mission Forward's official position, like that of many providers of criminal justice services, was to view crime as resulting from one primary deficiency in personhood: idleness. To rectify this, their policy was to fashion prototypical neoliberal entrepreneurs: self‐motivated and self‐reliant individualists whose primary concern is making money and who could achieve this goal no matter what the circumstances. In contrast, ex‐prisoners experienced a loss of personhood when they became marked as criminals by their friends and neighbors. To address this, ex‐prisoners were concerned with using the contracts, exchanges, and interactions associated with their entrepreneurial ventures to rebuild the social ties that their crimes and subsequent incarceration had damaged and thereby reclaim personhood. This article argues that these divergent uses of entrepreneurship as a rehabilitative and reintegrative tool provide new insights into the nature of entrepreneurship and into the establishment and reestablishment of both personhood and social ties through economic exchange.
Skills for forecasting space weather
Authors: Austin H. J. , Savani N. P.
Published: January 2018

Coronal mass ejections (CMEs) from the Sun can have severe impacts on the Earth environment in the form of geomagnetic storms. These storms pose a risk to the global technological infrastructure, making the prediction of these events imperative. In this paper, we have broadened the statistical verification of the Bz4Cast tool, the first empirically‐driven model to forecast solar wind magnetic vectors inside a CME prior to their Earth arrival. Twenty‐five CME events (between 2012 and 2016) have been tested with the Bz4Cast model, and the skills have been compared to the heuristic approach of NOAA’s Space Weather Prediction Center (SWPC) G‐scale for 3‐day geomagnetic storm forecasts. For a broad range of scores, and within uncertainty, the Bz4Cast architecture provided the same skill as the experienced on‐duty forecasters at SWPC. The most prominent difference is that the Bz4Cast architecture provides a slightly higher false alarm ratio than the SWPC 3‐day forecast.
Computational methods for birth‐death processes
Authors: Crawford Forrest W. , Ho Lam Si Tung , Suchard Marc A.
Published: January 2018

Many important stochastic counting models can be written as general birth‐death processes (BDPs). BDPs are continuous‐time Markov chains on the non‐negative integers in which only jumps to adjacent states are allowed. BDPs can be used to easily parameterize a rich variety of probability distributions on the non‐negative integers, and straightforward conditions guarantee that these distributions are proper. BDPs also provide a mechanistic interpretation—birth and death of actual particles or organisms—that has proven useful in evolution, ecology, physics, and chemistry. Although the theoretical properties of general BDPs are well understood, traditionally statistical work on BDPs has been limited to the simple linear (Kendall) process. Aside from a few simple cases, it remains impossible to find analytic expressions for the likelihood of a discretely‐observed BDP, and computational difficulties have hindered development of tools for statistical inference. But the gap between BDP theory and practical methods for estimation has narrowed in recent years. There are now robust methods for evaluating likelihoods for realizations of BDPs: finite‐time transition, first passage, equilibrium probabilities, and distributions of summary statistics that arise commonly in applications. Recent work has also exploited the connection between continuously‐ and discretely‐observed BDPs to derive EM algorithms for maximum likelihood estimation. Likelihood‐based inference for previously intractable BDPs is much easier than previously thought and regression approaches analogous to Poisson regression are straightforward to derive. In this review, we outline the basic mathematical theory for BDPs and demonstrate new tools for statistical inference using data from BDPs.WIREs Comput Stat2018, 10:e1423. doi: 10.1002/wics.1423

This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Bayesian Methods and Theory

Statistical and Graphical Methods of Data Analysis > Modeling Methods and Algorithms

Applications of Computational Statistics > Computational Chemistry
Phase-Stable, Multi-μJ Femtosecond Pulses from a Repetition-Rate Tunable Ti:Sa-Oscillator-Seeded Yb-Fiber Amplifier
Authors: Saule T. , Holzberger S. , De Vries O. , Plötner M. , Limpert J. , Tünnermann A. , Pupeza I.
Published: January 2018

We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The μJ-level output is spectrally broadened in a solid-core fiber and compressed to ~30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.
High-Precision Spectroscopy of the HD+ Molecule at the 1-p.p.b. Level
Authors: Biesheuvel J. , Karr J.-Ph. , Hilico L. , Eikema K. S. E. , Ubachs W. , Koelemeij J. C. J.
Published: January 2018

Recently we reported a high-precision optical frequency measurement of the (v, L): (0, 2)

$$ \to $$

→

(8, 3) vibrational overtone transition in trapped deuterated molecular hydrogen (HD+) ions at 10 mK temperature. Achieving a resolution of 0.85 parts-per-billion (p.p.b.), we found the experimental value [ν
0 = 383, 407, 177.38 (41) MHz] to be in agreement with the value from molecular theory [ν
th 383, 407, 177.150 (15) MHz] within 0.6 (1.1) p.p.b. (Biesheuvel et al. in Nat Commun 7:10385, 2016). This enabled an improved test of molecular theory (including QED), new constraints on the size of possible effects due to ‘new physics,’ and the first determination of the proton–electron mass ratio from a molecule. Here, we provide the details of the experimental procedure, spectral analysis, and the assessment of systematic frequency shifts. Our analysis focuses in particular on deviations of the HD+ velocity distribution from thermal (Gaussian) distributions under the influence of collisions with fast ions produced during (laser-induced) chemical reactions, as such deviations turn out to significantly shift the hyperfine-less vibrational frequency as inferred from the saturated and Doppler-broadened spectrum, which contains partly unresolved hyperfine structure.
All Polarization-Maintaining Fiber Laser Architecture for Robust Femtosecond Pulse Generation
Authors: Hänsel Wolfgang , Hoogland Heinar , Giunta Michele , Schmid Sebastian , Steinmetz Tilo , Doubek Ralf , Mayer Peter , Dobner Sven , Cleff Carsten , Fischer Marc , Holzwarth Ronald
Published: January 2018

We report on a novel architecture for robust mode-locked femtosecond fiber lasers using a nonlinear optical loop mirror with all polarization-maintaining fibers. Due to a nonreciprocal phase shift, the loop mirror can be operated in a compact and efficient reflection mode, offering the possibility to reach high repetition rates and easy implementation of tuning elements. In particular, longitudinal mode spacing and carrier-envelope offset frequency may be controlled in order to operate the laser as an optical frequency comb. We demonstrate femtosecond pulse generation at three different wavelengths (1030, 1565, and 2050 nm) using Ytterbium, Erbium, and co-doped Thulium–Holmium as gain media, respectively. Robust operation is achieved for a wide range of parameters, including repetition rates from 10 to 250 MHz.
New Avenues for Matter-Wave-Enhanced Spectroscopy
Authors: Rodewald Jonas , Haslinger Philipp , Dörre Nadine , Stickler Benjamin A. , Shayeghi Armin , Hornberger Klaus , Arndt Markus
Published: January 2018

We present matter-wave interferometry as a tool to advance spectroscopy for a wide class of nanoparticles, clusters and molecules. The high sensitivity of de Broglie interference fringes to external perturbations enables measurements in the limit of an individual particle absorbing only a single photon on average, or even no photon at all. The method allows one to extract structural and electronic information from the loss of the interference contrast. It is minimally invasive and works even for dilute ensembles.
Shifting the Phase of a Coherent Beam with a $$ {}^{\mathbf{174}}{\mathbf{Yb}}^{+} $$ Ion: Influence of the Scattering Cross Section
Authors: Fischer Martin , Srivathsan Bharath , Alber Lucas , Weber Markus , Sondermann Markus , Leuchs Gerd
Published: January 2018

We discuss and measure the phase shift imposed onto a radially polarized light beam when focusing it onto an

$$ {}^{174}{\mathrm{Yb}}^{+} $$

174

Yb
+

ion. In the derivation of the expected phase shifts, we include the properties of the involved atomic levels. Furthermore, we emphasize the importance of the scattering cross section and its relation to the efficiency for coupling the focused light to an atom. The phase shifts found in the experiment are compatible with the expected ones when accounting for known deficiencies of the focusing optics and the motion of the trapped ion at the Doppler limit of laser cooling (Hänsch and Schawlow in Opt Commun 13:68–69, 1975).
Extraction of Enhanced, Ultrashort Laser Pulses from a Passive 10-MHz Stack-and-Dump Cavity
Authors: Breitkopf Sven , Wunderlich Stefano , Eidam Tino , Shestaev Evgeny , Holzberger Simon , Gottschall Thomas , Carstens Henning , Tünnermann Andreas , Pupeza Ioachim , Limpert Jens
Published: January 2018

Periodic dumping of ultrashort laser pulses from a passive multi-MHz repetition-rate enhancement cavity is a promising route towards multi-kHz repetition-rate pulses with Joule-level energies at an unparalleled average power. Here, we demonstrate this so-called stack-and-dump scheme with a 30-m-long cavity. Using an acousto-optic modulator, we extract pulses of 0.16 mJ at 30-kHz repetition rate, corresponding to 65 stacked input pulses, representing an improvement in three orders of magnitude over previously extracted pulse energies. The ten times longer cavity affords three essential benefits over former approaches. First, the time between subsequent pulses is increased to 100 ns, relaxing the requirements on the switch. Second, it allows for the stacking of strongly stretched pulses (here from 800 fs to 1.5 ns), thus mitigating nonlinear effects in the cavity optics. Third, the choice of a long cavity offers increased design flexibility with regard to thermal robustness, which will be crucial for future power scaling. The herein presented results constitute a necessary step towards stack-and-dump systems providing access to unprecedented laser parameter regimes.
From Quantum Transitions to Electronic Motions
Authors: Krausz Ferenc
Published: January 2018

Laser spectroscopy and chronoscopy permit precision measurement of quantum transitions and captures atomic-scale dynamics, respectively. Frequency- and time-domain metrology ranks among the supreme laser disciplines in fundamental science. For decades, these fields evolved independently, without interaction and synergy between them. This has changed profoundly with controlling the position of the equidistant frequency spikes of a mode-locked laser oscillator. By the self-referencing technique invented by Theodor Hänsch, the comb can be coherently linked to microwaves and used for precision measurements of energy differences between quantum states. The resultant optical frequency synthesis has revolutionized precision spectroscopy. Locking the comb lines to the resonator round-trip frequency by the same approach has given rise to laser pulses with controlled field oscillations. This article reviews, from a personal perspective, how the bridge between frequency- and time-resolved metrology emerged on the turn of the millennium and how synthesized several-cycle laser fields have been instrumental in establishing the basic tools and techniques for attosecond science.
Quantum Regime of a Free-Electron Laser: Relativistic Approach
Authors: Kling Peter , Sauerbrey Roland , Preiss Paul , Giese Enno , Endrich Rainer , Schleich Wolfgang P.
Published: January 2018

In the quantum regime of the free-electron laser, the dynamics of the electrons is not governed by continuous trajectories but by discrete jumps in momentum. In this article, we rederive the two crucial conditions to enter this quantum regime: (1) a large quantum mechanical recoil of the electron caused by the scattering with the laser and the wiggler field and (2) a small energy spread of the electron beam. In contrast to our recent approach based on nonrelativistic quantum mechanics in a co-moving frame of reference, we now pursue a model in the laboratory frame employing relativistic quantum electrodynamics.
Assessment of Cu applications in two contrasting soils—effects on soil microbial activity and the fungal community structure
Authors: Keiblinger Katharina M. , Schneider Martin , Gorfer Markus , Paumann Melanie , Deltedesco Evi , Berger Harald , Jöchlinger Lisa , Mentler Axel , Zechmeister-Boltenstern Sophie , Soja Gerhard , Zehetner Franz
Published: January 2018

Copper (Cu)-based fungicides have been used in viticulture to prevent downy mildew since the end of the 19th century, and are still used today to reduce fungal diseases. Consequently, Cu has built up in many vineyard soils, and it is still unclear how this affects soil functioning. The present study aimed to assess the short and medium-term effects of Cu contamination on the soil fungal community. Two contrasting agricultural soils, an acidic sandy loam and an alkaline silt loam, were used for an eco-toxicological greenhouse pot experiment. The soils were spiked with a Cu-based fungicide in seven concentrations (0–5000 mg Cu kg−1soil) and alfalfa was grown in the pots for 3 months. Sampling was conducted at the beginning and at the end of the study period to test Cu toxicity effects on total microbial biomass, basal respiration and enzyme activities. Fungal abundance was analysed by ergosterol at both samplings, and for the second sampling, fungal community structure was evaluated via ITS amplicon sequences. Soil microbial biomass C as well as microbial respiration rate decreased with increasing Cu concentrations, with EC50ranging from 76 to 187 mg EDTA-extractable Cu kg−1soil. Oxidative enzymes showed a trend of increasing activity at the first sampling, but a decline in peroxidase activity was observed for the second sampling. We found remarkable Cu-induced changes in fungal community abundance (EC50ranging from 9.2 to 94 mg EDTA-extractable Cu kg−1soil) and composition, but not in diversity. A large number of diverse fungi were able to thrive under elevated Cu concentrations, though within the order ofHypocrealesseveral species declined. A remarkable Cu-induced change in the community composition was found, which depended on the soil properties and, hence, on Cu availability.
Physics-Informed Network Models: a Data Science Approach to Metal Design
Authors: Verma Amit K. , French Roger H. , Carter Jennifer L. W.
Published: January 2018

Functional graded materials (FGM) allow for reconciliation of conflicting design constraints at different locations in the material. This optimization requires a priori knowledge of how different architectural measures are interdependent and combine to control material performance. In this work, an aluminum FGM was used as a model system to present a new network modeling approach that captures the relationship between design parameters and allows an easy interpretation. The approach, in an un-biased manner, successfully captured the expected relationships and was capable of predicting the hardness as a function of composition.
Metaphors and Paradigms of the Language Animal—or—The Advantage of seeing “Time Is a Resource” as a Paradigm
Authors: KEDING GESCHE
Published: January 2018

One of the features of an encompassing account of language that Charles Taylor examines in Chapter Five, “The Figuring Dimension of Language,” ofThe Language Animalis a special kind of metaphor, which is rooted in the embodiment of humans. Their perspective-taking, their intuition of position in space, etc., provide ‘structural templates’ for thinking and leave their traces in their expressions. Taylor compares these metaphors with paradigms. My paper discusses the differences between the two. Taylor’s example ‘Time Is a Resource’ is understood more deeply if seen as a paradigm, i.e., a set of beliefs and practices, instead of as a ‘structural template,’ i.e., rooted in embodiment.
The Creative Force of Discourse and the Appearance of Politics: Reading Charles Taylor with the Political Theory of Jacques Rancière
Authors: EMMERICH MARC
Published: January 2018

Does the creative force of discourse Taylor describes enable the subaltern to speak for themselves? To answer this question, I underlay Jacques Rancière’s concept of politics. I correlate Charles Taylor’s opposition of HLC- and HHH-language theories to Rancière’s distinction of ‘politics’ and ‘police.’ However, since the creative force of discourse also re-enacts human order through rituals and repetitions, it is not political per se. I discuss Taylor’s example of the “avuncular” relationship to show at which point the creative force could turn into a fundament of politics and where it doesn’t.
DEFINITE DISCOURSE-NEW REFERENCE IN L1 AND L2
Authors: Crosthwaite Peter , Yeung Yuk , Bai Xuefei , Lu Li , Bae Yeonsuk
Published: January 2018

Definite discourse-new bridging reference (e.g., a school …the teacher; Clark, 1975) is a complex syntax-pragmatic component of referential movement, one that is subject to relatively opaque form-function contingency compared with forms used for discourse-old reference, and one that is especially prone to crosslinguistic influence. Research shows Asian second language (L2) learners of English struggle to produce bridging reference appropriately, yet little research has been done on the L2 production of bridging in Asian languages. We collected oral picture sequence narrative data from 80 lower-intermediate L2 Mandarin learners from first language (L1) English (+ article, n = 23) and L1 Korean and Japanese (- article, n = 57) backgrounds, alongside equivalent L1 data. Speakers of article-L1s were more likely than those from article-less L1s to use numeral + classifier noun phrases (NPs) for nonbridging referents and demonstrative + classifier NPs when introducing bridging referents, essentially (and infelicitously) using these constructions as de facto English-like indefinite/definite articles in their L2 Mandarin production. Speakers of article-less languages infelicitously marked bridging relations with nonbridging forms. These findings confirm substantial crosslinguistic difficulties for the L2 marking of this complex syntax-pragmatic phenomenon across relatively underexplored L1/L2 pairs.
Droperidol dropped; consultants not consulted
Authors: Reid Gavin , Hughson Mark
Published: January 2018

Aims and Method

We conducted a postal questionnaire survey of the practice of rapid tranquillisation among 215 consultant psychiatrists in the West of Scotland, before and after the withdrawal of droperidol by the manufacturer.

Results

One hundred and eighty questionnaires (84% of those sent) were returned. Droperidol had been used extensively, often combined with lorazepam, for rapid tranquillisation. The main replacement suggested for droperidol was haloperidol. About half of the respondents to our survey chose to comment on the withdrawal of droperidol. More than half of the comments were unfavourable, including lack of an adequate replacement and lack of consultation with the psychiatric profession.

Clinical Implications

The abrupt withdrawal of droperidol, partly for commercial reasons, was regrettable. There was no time for an adequate evaluation of possible replacement medications and a lack of consultation with the profession regarding the impact on clinical care.
Service innovations
Authors: Richman Anna , Wilson Ken , Scally Lynn , Edwards Paul , Wood Jacqueline
Published: January 2018

Aims and Method

We describe activity and outcome concerning a consecutive series of older community patients referred to an outreach support team while waiting for acute psychiatric admission.

Results

Forty patients on an admissions waiting list who were referred to the outreach support team were followed up. Each patient was reassessed for admission by the responsible medical officer when an in-patient bed became available. Thirty patients who would have been admitted (if a bed had been available at the time of the first assessment) remained at home and did not need hospitalisation.

Clinical Implications

This study suggests that intensive domiciliary support might offer an acceptable form of crisis intervention for older people with mental illness. Further research is needed before generalisation of these findings can be recommended.
Thermoluminescent microparticle thermal history sensors
Authors: Talghader Joseph J. , Mah Merlin L. , Yukihara Eduardo G. , Coleman Adam C.
Published: January 2018

While there are innumerable devices that measure temperature, the nonvolatile measurement of thermal history is far more difficult, particularly for sensors embedded in extreme environments such as fires and explosions. In this review, an extensive analysis is given of one such technology: thermoluminescent microparticles. These are transparent dielectrics with a large distribution of trap states that can store charge carriers over very long periods of time. In their simplest form, the population of these traps is dictated by an Arrhenius expression, which is highly dependent on temperature. A particle with filled traps that is exposed to high temperatures over a short period of time will preferentially lose carriers in shallow traps. This depopulation leaves a signature on the particle luminescence, which can be used to determine the temperature and time of the thermal event. Particles are prepared—many months in advance of a test, if desired—by exposure to deep ultraviolet, X-ray, beta, or gamma radiation, which fills the traps with charge carriers. Luminescence can be extracted from one or more particles regardless of whether or not they are embedded in debris or other inert materials. Testing and analysis of the method is demonstrated using laboratory experiments with microheaters and high energy explosives in the field. It is shown that the thermoluminescent materials LiF:Mg,Ti, MgB4O7:Dy,Li, and CaSO4:Ce,Tb, among others, provide accurate measurements of temperature in the 200 to 500 °C range in a variety of high-explosive environments.
Oxidation of Atg3 and Atg7 mediates inhibition of autophagy
Authors: Frudd Karen , Burgoyne Thomas , Burgoyne Joseph Robert
Published: January 2018

Macroautophagy (autophagy) is a crucial cellular stress response for degrading defective macromolecules and organelles, as well as providing bioenergetic intermediates during hypoxia and nutrient deprivation. Here we report a thiol-dependent process that may account for impaired autophagy during aging. This is through direct oxidation of key autophagy-related (Atg) proteins Atg3 and Atg7. When inactive Atg3 and Atg7 are protected from oxidation due to stable covalent interaction with their substrate LC3. This interaction becomes transient upon activation of Atg3 and Atg7 due to transfer of LC3 to phosphatidylethanolamine (lipidation), a process crucial for functional autophagy. However, loss in covalent-bound LC3 also sensitizes the catalytic thiols of Atg3 and Atg7 to inhibitory oxidation that prevents LC3 lipidation, observed in vitro and in mouse aorta. Here findings provide a thiol-dependent process for negatively regulating autophagy that may contribute to the process of aging, as well as therapeutic targets to regulate autophagosome maturation.