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Aim: We aimed to develop the first references for body height, body weight and body mass index (BMI) for boys based on the individual developmental tempo with respect to their voice break status. Methods: We re-analysed data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS study) on body height, body weight and body mass index based on the voice break, or mutation, in 3956 boys aged 10-17 years. We used the LMS method to construct smoothed references centiles for the studied variables in premutational, mutational and postmutational boys. Results: Body height, body weight and BMI differed significantly (p < 0.001) between the different stages of voice break. On average, boys were 5.9 cm taller, 5.8 kg heavier and had a 0.7 kg/m(2) higher BMI with every higher stage of voice break. Currently used growth references for chronological age in comparison with maturity-related references led to an average of 5.4% of boys being falsely classified as overweight.
This article explores the practice and political significance of politicians’ journeys to conflict zones. It focuses on the German example, looking at field trips to theatres of international intervention as a way of first-hand knowledge in policymaking. Paying tribute to Lisa Smirl and her work on humanitarian spaces, objects and imaginaries and on liminality in aid worker biographies, two connected arguments are developed. First, through the exploration of the routinized practices of politicians’ field trips the article shows how these journeys not only remain confined to the ‘auxiliary space’ of aid/intervention, but that it is furthermore a staged reality of this auxiliary space that most politicians experience on their journeys. The question is then asked, second, what politicians actually experience on their journeys and how their experiences relate to their policy knowledge about conflict and intervention. It is shown that political field trips enable sensory/affectual, liminoid and liminal experiences, which have functions such as authority accumulation, agenda setting, community building, and civilizing domestic politics, while at the same time reinforcing, in most cases, pre-existing conflict and intervention imaginaries.
The central rift of the Red Sea has 25 brine pools with different physical and geochemical characteristics. Atlantis II (ATIID), Discovery Deeps (DD) and Chain Deep (CD) are characterized by high salinity, temperature and metal content. Several studies reported microbial communities in these brine pools, but few studies addressed the brine pool sediments. Therefore, sediment cores were collected from ATIID, DD, CD brine pools and an adjacent brine-influenced site. Sixteen different lithologic sediment sections were subjected to shotgun DNA pyrosequencing to generate 1.47 billion base pairs (1.47 x 10(9) bp). We generated sediment-specific reads and attempted to annotate all reads. We report the phylogenetic and biochemical uniqueness of the deepest ATIID sulfur-rich brine pool sediments. In contrary to all other sediment sections, bacteria dominate the deepest ATIID sulfur-rich brine pool sediments. This decrease in virus-to-bacteria ratio in selected sections and depth coincided with an overrepresentation of mobile genetic elements. Skewing in the composition of viruses-to-mobile genetic elements may uniquely contribute to the distinct microbial consortium in sediments in proximity to hydrothermally active vents of the Red Sea and possibly in their surroundings, through differential horizontal gene transfer.
It is argued that, despite differences in cultural norms and practices, the evidence for a link between violent media use and aggression is remarkably consistent across different countries. Along with evidence that different operationalizations of violent media use also converge across countries, these findings strengthen the conclusion that violent media are a risk factor for aggression and validate the psychological explanations for these effects. However, we need comparative studies based on a consistent methodology and a theory-based selection of cultural difference variables to properly examine the potential impact of culture on the association between violent media use and aggression.
Context. For the spectral analysis of high-resolution and high signal-to-noise (S/N) spectra of hot stars, state-of-the-art non-local thermodynamic equilibrium (NLTE) model atmospheres are mandatory. These are strongly dependent on the reliability of the atomic data that is used for their calculation. Aims. New Kr IV-VII oscillator strengths for a large number of lines enable us to construct more detailed model atoms for our NLTE model-atmosphere calculations. This enables us to search for additional Kr lines in observed spectra and to improve Kr abundance determinations. Methods. We calculated Kr IV-VII oscillator strengths to consider radiative and collisional bound-bound transitions in detail in our NLTE stellar-atmosphere models for the analysis of Kr lines that are exhibited in high-resolution and high S/N ultraviolet (UV) observations of the hot white dwarf RE 0503-289. Results. We reanalyzed the effective temperature and surface gravity and determined T-eff = 70 000 +/- 2000 K and log (g/cm s(-2)) = 7.5 +/- 0.1. We newly identified ten Kr V lines and one Kr vi line in the spectrum of RE 0503-289. We measured a Kr abundance of 3.3 +/- 0.3 (logarithmic mass fraction). We discovered that the interstellar absorption toward RE 0503-289 has a multi-velocity structure within a radial-velocity interval of -40 km s(-1) < upsilon(rad) < +18 km s(-1). Conclusions. Reliable measurements and calculations of atomic data are a prerequisite for state-of-the-art NLTE stellar-atmosphere modeling. Observed Kr V-VII line profiles in the UV spectrum of the white dwarf RE 0503-289 were simultaneously well reproduced with our newly calculated oscillator strengths.
The valence-excited states of ferric and ferrous hexacyanide ions in aqueous solution were mapped by resonant inelastic X-ray scattering (RIXS) at the Fe L-2,L-3 and N K edges. Probing of both the central Fe and the ligand N atoms enabled identification of the metal-and ligand-centered excited states, as well as ligand-to-metal and metal-to-ligand charge-transfer excited states. Ab initio calculations utilizing the RASPT2 method were used to simulate the Fe L-2,L-3-edge RIXS spectra and enabled quantification of the covalencies of both occupied and empty orbitals of pi and sigma symmetry. We found that pi back-donation in the ferric complex is smaller than that in the ferrous complex. This is evidenced by the relative amounts of Fe 3d character in the nominally 2 pi CN- molecular orbital of 7% and 9% in ferric and ferrous hexacyanide, respectively. Utilizing the direct sensitivity of Fe L-3-edge RIXS to the Fe 3d character in the occupied molecular orbitals, we also found that the donation interactions are dominated by sigma bonding. The latter was found to be stronger in the ferric complex, with an Fe 3d contribution to the nominally 5 sigma CN- molecular orbitals of 29% compared to 20% in the ferrous complex. These results are consistent with the notion that a higher charge at the central metal atom increases donation and decreases back-donation.
The very high energy (VHE; E > 100 GeV) blazar Markarian 501 was observed between April 17 and May 5 (MJD 54 938-54 956), 2009, as part of an extensive multiwavelength campaign from radio to VHE. Strong VHE yray activity was detected on May 1st with Whipple and VERITAS, when the flux (E > 400 GeV) increased to 10 times the preflare baseline flux (3.9 x 10(-11) ph cm(-2) s(-1)), reaching five times the flux of the Crab Nebula. This coincided with a decrease in the optical polarization and a rotation of the polarization angle by 15. This VHE flare showed a fast flux variation with an increase of a factor similar to 4 in 25 min, and a falling time of similar to 50 min. We present the observations of the quiescent state previous to the flare and of the high state after the flare, focusing on the flux and spectral variability from Whipple, VERITAS, Fermi-LAT, RXTE, and Swift combined with optical and radio data.
We present an X-ray-optical cross-correlator for the soft (> 150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%. (C) 2016 Author(s).
We present an X-ray-optical cross-correlator for the soft (> 150 eV) up to the hard X-ray regime based on a molybdenum-silicon superlattice. The cross-correlation is done by probing intensity and position changes of superlattice Bragg peaks caused by photoexcitation of coherent phonons. This approach is applicable for a wide range of X-ray photon energies as well as for a broad range of excitation wavelengths and requires no external fields or changes of temperature. Moreover, the cross-correlator can be employed on a 10 ps or 100 fs time scale featuring up to 50% total X-ray reflectivity and transient signal changes of more than 20%. (C) 2016 Author(s).
We present results from multiwavelength observations of the BL Lacertae object 1ES 1741 + 196, including results in the very high energy gamma-ray regime using the Very Energetic Radiation Imaging Telescope Array System (VERITAS). The VERITAS time-averaged spectrum, measured above 180 GeV, is well modelled by a power law with a spectral index of 2.7 +/- 0.7(stat) +/- 0.2(syst). The integral flux above 180 GeV is (3.9 +/- 0.8(stat) +/- 1.0(syst)) x 10(-8) m(-2) s(-1), corresponding to 1.6 per cent of the Crab nebula flux on average. The multiwavelength spectral energy distribution of the source suggests that 1ES 1741+196 is an extreme-high-frequency-peaked BL Lacertae object. The observations analysed in this paper extend over a period of six years, during which time no strong flares were observed in any band. This analysis is therefore one of the few characterizations of a blazar in a non-flaring state.
Storm runoff from the Marikina River Basin frequently causes flood events in the Philippine capital region Metro Manila. This paper presents and evaluates a system to predict short-term runoff from the upper part of that basin (380km(2)). It was designed as a possible component of an operational warning system yet to be installed. For the purpose of forecast verification, hindcasts of streamflow were generated for a period of 15 months with a time-continuous, conceptual hydrological model. The latter was fed with real-time observations of rainfall. Both ground observations and weather radar data were tested as rainfall forcings. The radar-based precipitation estimates clearly outperformed the raingauge-based estimates in the hydrological verification. Nevertheless, the quality of the deterministic short-term runoff forecasts was found to be limited. For the radar-based predictions, the reduction of variance for lead times of 1, 2 and 3hours was 0.61, 0.62 and 0.54, respectively, with reference to a no-forecast scenario, i.e. persistence. The probability of detection for major increases in streamflow was typically less than 0.5. Given the significance of flood events in the Marikina Basin, more effort needs to be put into the reduction of forecast errors and the quantification of remaining uncertainties.
QuestionHow important is the effect of micro-relief and vegetation type on the characteristics of vascular plants and bryophytes in low-centred polygons? LocationSiberian Arctic, Russia. MethodsEight low-centred polygons in northern Siberia were surveyed for vegetation along transects running from the rim to the pond via the rim-pond transition of each polygon and across a vegetation type gradient from open forest to tundra. ResultsThe cover of vascular plants and bryophytes displays no significant differences between the rim and rim-pond transition but is significantly lower in the pond section of the polygons. Alpha-diversity of vascular plants decreases strongly from rim to pond, whereas bryophyte diversity in pond plots is significantly distinct from the rim and the rim-pond transition. There is no clear trend in cover for either plant group along the vegetation type transect and only a weak trend in -diversity. However, both gradients are reflected in the compositional turnover. The applied indicator species analysis identified taxa characteristic of certain environmental conditions. Among others, we found vascular plants primarily characteristic of the rim and bryophyte taxa characteristic of each micro-relief level and vegetation type. ConclusionsThe observed gradual pattern in -diversity and composition of polygonal vegetation suggests that micro-relief is the main driver of changes in the vegetation composition, while vegetation type and the related forest cover change are of subordinate importance for polygonal vegetation patterns along the Siberian tree line.
By reducing current velocity, tidal marsh vegetation can diminish storm surges and storm waves. Conversely, currents often exert high mechanical stresses onto the plants and hence affect vegetation structure and plant characteristics. In our study, we aim at analysing this interaction from both angles. On the one hand, we quantify the reduction of current velocity by Bolboschoenus maritimus, and on the other hand, we identify functional traits of B. maritimus’ ramets along environmental gradients. Our results show that tidal marsh vegetation is able to buffer a large proportion of the flow velocity at currents under normal conditions. Cross-shore current velocity decreased with distance from the marsh edge and was reduced by more than 50% after 15 m of vegetation. We were furthermore able to show that plants growing at the marsh edge had a significantly larger diameter than plants from inside the vegetation. We found a positive correlation between plant thickness and cross-shore current which could provide an adaptive value in habitats with high mechanical stress. With the adapted morphology of plants growing at the highly exposed marsh edge, the entire vegetation belt is able to better resist the mechanical stress of high current velocities. This self-adaptive effect thus increases the ability of B. maritimus to grow and persist in the pioneer zone and may hence better contribute to ecosystem-based coastal protection by reducing current velocity.
Background: Epidemiological research indicates that the use of prescription drugs to enhance cognitive functioning is prevalent in Western countries, however, research on this phenomenon in Arab countries is lacking. Our study aimed to investigate the frequency of neuroenhancement (NE) using prescription drugs in a sample of employees in Jordan. Methods: A sample of 1186 employees (37.11 +/- 8.37 years old, 495 female), of whom 723 (35.65 +/- 7.53 years old, 396 female) served as teachers, completed a paper-pencil questionnaire. The single sample count technique (SSC) was used in order to secure confidential, self-reporting of prescription drug NE. Results: The 12-month prevalence of NE, estimated with the SSC was 15.43%. At 26.16%, the prevalence estimate was markedly higher in the subsample of teachers compared to non-teachers, 0.29%. Surprisingly, 336 participants did not use the SSC and directly affirmed or denied prescription drug NE. These direct responses yielded a prevalence of 11.57% for the full sample, 9.73% for the teachers and 15.60% for the non-teachers. Conclusion: This is the first study of the frequency of NE in an Arab sample. Results indicate that the use of prescription drug NE is not limited to Western countries and that teachers in Jordan might constitute a high-risk population. Further, participants seem to differ in their use of indirect estimation methods for reporting prescription drug NE. For future research, it might be useful to triangulate standard self reports and indirect estimation methods to assess NE. Possible cultural differences and specific high-risk populations for NE should be investigated further. (C) 2015 Elsevier B.V. All rights reserved.
Using Causal Effect Networks to Analyze Different Arctic Drivers of Midlatitude Winter Circulation
(2016)
In recent years, the Northern Hemisphere midlatitudes have suffered from severe winters like the extreme 2012/13 winter in the eastern United States. These cold spells were linked to a meandering upper-tropospheric jet stream pattern and a negative Arctic Oscillation index (AO). However, the nature of the drivers behind these circulation patterns remains controversial. Various studies have proposed different mechanisms related to changes in the Arctic, most of them related to a reduction in sea ice concentrations or increasing Eurasian snow cover. Here, a novel type of time series analysis, called causal effect networks (CEN), based on graphical models is introduced to assess causal relationships and their time delays between different processes. The effect of different Arctic actors on winter circulation on weekly to monthly time scales is studied, and robust network patterns are found. Barents and Kara sea ice concentrations are detected to be important external drivers of the midlatitude circulation, influencing winter AO via tropospheric mechanisms and through processes involving the stratosphere. Eurasia snow cover is also detected to have a causal effect on sea level pressure in Asia, but its exact role on AO remains unclear. The CEN approach presented in this study overcomes some difficulties in interpreting correlation analyses, complements model experiments for testing hypotheses involving teleconnections, and can be used to assess their validity. The findings confirm that sea ice concentrations in autumn in the Barents and Kara Seas are an important driver of winter circulation in the midlatitudes.
Recent research has indicated that university students sometimes use caffeine pills for neuroenhancement (NE; non-medical use of psychoactive substances or technology to produce a subjective enhancement in psychological functioning and experience), especially during exam preparation. In our factorial survey experiment, we manipulated the evidence participants were given about the prevalence of NE amongst peers and measured the resulting effects on the psychological predictors included in the Prototype-Willingness Model of risk behavior. Two hundred and thirty-one university students were randomized to a high prevalence condition (read faked research results overstating usage of caffeine pills amongst peers by a factor of 5; 50%), low prevalence condition (half the estimated prevalence; 5%) or control condition (no information about peer prevalence). Structural equation modeling confirmed that our participants’ willingness and intention to use caffeine pills in the next exam period could be explained by their past use of neuroenhancers, attitude to NE and subjective norm about use of caffeine pills whilst image of the typical user was a much less important factor. Provision of inaccurate information about prevalence reduced the predictive power of attitude with respect to willingness by 40-45%. This may be because receiving information about peer prevalence which does not fit with their perception of the social norm causes people to question their attitude. Prevalence information might exert a deterrent effect on NE via the attitude-willingness association. We argue that research into NE and deterrence of associated risk behaviors should be informed by psychological theory.
Recent research has indicated that university students sometimes use caffeine pills for neuroenhancement (NE; non-medical use of psychoactive substances or technology to produce a subjective enhancement in psychological functioning and experience), especially during exam preparation. In our factorial survey experiment, we manipulated the evidence participants were given about the prevalence of NE amongst peers and measured the resulting effects on the psychological predictors included in the Prototype-Willingness Model of risk behavior. Two hundred and thirty-one university students were randomized to a high prevalence condition (read faked research results overstating usage of caffeine pills amongst peers by a factor of 5; 50%), low prevalence condition (half the estimated prevalence; 5%) or control condition (no information about peer prevalence). Structural equation modeling confirmed that our participants’ willingness and intention to use caffeine pills in the next exam period could be explained by their past use of neuroenhancers, attitude to NE and subjective norm about use of caffeine pills whilst image of the typical user was a much less important factor. Provision of inaccurate information about prevalence reduced the predictive power of attitude with respect to willingness by 40-45%. This may be because receiving information about peer prevalence which does not fit with their perception of the social norm causes people to question their attitude. Prevalence information might exert a deterrent effect on NE via the attitude-willingness association. We argue that research into NE and deterrence of associated risk behaviors should be informed by psychological theory.
Recent research has indicated that university students sometimes use caffeine pills for neuroenhancement (NE; non-medical use of psychoactive substances or technology to produce a subjective enhancement in psychological functioning and experience), especially during exam preparation. In our factorial survey experiment, we manipulated the evidence participants were given about the prevalence of NE amongst peers and measured the resulting effects on the psychological predictors included in the Prototype-Willingness Model of risk behavior. Two hundred and thirty-one university students were randomized to a high prevalence condition (read faked research results overstating usage of caffeine pills amongst peers by a factor of 5; 50%), low prevalence condition (half the estimated prevalence; 5%) or control condition (no information about peer prevalence). Structural equation modeling confirmed that our participants’ willingness and intention to use caffeine pills in the next exam period could be explained by their past use of neuroenhancers, attitude to NE and subjective norm about use of caffeine pills whilst image of the typical user was a much less important factor. Provision of inaccurate information about prevalence reduced the predictive power of attitude with respect to willingness by 40-45%. This may be because receiving information about peer prevalence which does not fit with their perception of the social norm causes people to question their attitude. Prevalence information might exert a deterrent effect on NE via the attitude-willingness association. We argue that research into NE and deterrence of associated risk behaviors should be informed by psychological theory.
Sixteen new ionic liquids (ILs) with tetraethylammonium, 1-butyl-3-methylimidazolium, 3-methyl-1-octylimidazolium and tetrabutylphosphonium cations paired with 2-substituted 4,5-dicyanoimidazolate anions (substituent at C2 = methyl, trifluoromethyl, pentafluoroethyl, N,N′-dimethyl amino and nitro) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of cation and anion type and structure of the resulting ILs, including several room temperature ionic liquids (RTILs), are reflected in the crystallization, melting points and thermal decomposition of the ILs. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of −22 to −71 °C. We selected one of the newly designed ILs due to its bigger size, compared to the common conventional IL anion and high electron-withdrawing nitrile group leads to an overall stabilization anion that may stabilize the metal nanoparticles. Stable and better separated iron and silver nanoparticles are obtained by the decomposition of corresponding Fe2(CO)9 and AgPF6, respectively, under N2-atmosphere in newly designed nitrile functionalized 4,5-dicyanoimidazolate anion based IL. Very small and uniform size for Fe-nanoparticles of about 1.8 ± 0.6 nm were achieved without any additional stabilizers or capping molecules. Comparatively bigger size of Ag-nanoparticles was obtained through the reduction of AgPF6 by hydrogen gas. Additionally, the AgPF6 precursor was decomposed under microwave irradiation (MWI), fabricating nut-in-shell-like, that is, core-separated-from-shell Ag-nano-structures.
Sixteen new ionic liquids (ILs) with tetraethylammonium, 1-butyl-3-methylimidazolium, 3-methyl-1-octylimidazolium and tetrabutylphosphonium cations paired with 2-substituted 4,5-dicyanoimidazolate anions (substituent at C2 = methyl, trifluoromethyl, pentafluoroethyl, N,N′-dimethyl amino and nitro) have been synthesized and characterized by using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA). The effects of cation and anion type and structure of the resulting ILs, including several room temperature ionic liquids (RTILs), are reflected in the crystallization, melting points and thermal decomposition of the ILs. ILs exhibited large liquid and crystallization ranges and formed glasses on cooling with glass transition temperatures in the range of −22 to −71 °C. We selected one of the newly designed ILs due to its bigger size, compared to the common conventional IL anion and high electron-withdrawing nitrile group leads to an overall stabilization anion that may stabilize the metal nanoparticles. Stable and better separated iron and silver nanoparticles are obtained by the decomposition of corresponding Fe2(CO)9 and AgPF6, respectively, under N2-atmosphere in newly designed nitrile functionalized 4,5-dicyanoimidazolate anion based IL. Very small and uniform size for Fe-nanoparticles of about 1.8 ± 0.6 nm were achieved without any additional stabilizers or capping molecules. Comparatively bigger size of Ag-nanoparticles was obtained through the reduction of AgPF6 by hydrogen gas. Additionally, the AgPF6 precursor was decomposed under microwave irradiation (MWI), fabricating nut-in-shell-like, that is, core-separated-from-shell Ag-nano-structures.
Background
Vitamin-D-binding protein (VDBP) is a low molecular weight protein that is filtered through the glomerulus as a 25-(OH) vitamin D 3/VDBP complex. In the normal kidney VDBP is reabsorbed and catabolized by proximal tubule epithelial cells reducing the urinary excretion to trace amounts. Acute tubular injury is expected to result in urinary VDBP loss. The purpose of our study was to explore the potential role of urinary VDBP as a biomarker of an acute renal damage.
Method
We included 314 patients with diabetes mellitus or mild renal impairment undergoing coronary angiography and collected blood and urine before and 24 hours after the CM application. Patients were followed for 90 days for the composite endpoint major adverse renal events (MARE: need for dialysis, doubling of serum creatinine after 90 days, unplanned emergency rehospitalization or death).
Results
Increased urine VDBP concentration 24 hours after contrast media exposure was predictive for dialysis need (no dialysis: 113.06 +/- 299.61ng/ml, n = 303; need for dialysis: 613.07 +/- 700.45 ng/ml, n = 11, Mean +/- SD, p < 0.001), death (no death during follow-up: 121.41 +/- 324.45 ng/ml, n = 306; death during follow-up: 522.01 +/- 521.86 ng/ml, n = 8; Mean +/- SD, p < 0.003) and MARE (no MARE: 112.08 +/- 302.00ng/ml, n = 298; MARE: 506.16 +/- 624.61 ng/ml, n = 16, Mean +/- SD, p < 0.001) during the follow-up of 90 days after contrast media exposure. Correction of urine VDBP concentrations for creatinine excretion confirmed its predictive value and was consistent with increased levels of urinary Kidney Injury Molecule1 (KIM-1) and baseline plasma creatinine in patients with above mentioned complications. The impact of urinary VDBP and KIM-1 on MARE was independent of known CIN risk factors such as anemia, preexisting renal failure, preexisting heart failure, and diabetes.
Conclusions
Urinary VDBP is a promising novel biomarker of major contrast induced nephropathy-associated events 90 days after contrast media exposure.
Background Vitamin-D-binding protein (VDBP) is a low molecular weight protein that is filtered through the glomerulus as a 25-(OH) vitamin D 3/VDBP complex. In the normal kidney VDBP is reabsorbed and catabolized by proximal tubule epithelial cells reducing the urinary excretion to trace amounts. Acute tubular injury is expected to result in urinary VDBP loss. The purpose of our study was to explore the potential role of urinary VDBP as a biomarker of an acute renal damage. Method We included 314 patients with diabetes mellitus or mild renal impairment undergoing coronary angiography and collected blood and urine before and 24 hours after the CM application. Patients were followed for 90 days for the composite endpoint major adverse renal events (MARE: need for dialysis, doubling of serum creatinine after 90 days, unplanned emergency rehospitalization or death). Results Increased urine VDBP concentration 24 hours after contrast media exposure was predictive for dialysis need (no dialysis: 113.06 +/- 299.61ng/ml, n = 303; need for dialysis: 613.07 +/- 700.45 ng/ml, n = 11, Mean +/- SD, p < 0.001), death (no death during follow-up: 121.41 +/- 324.45 ng/ml, n = 306; death during follow-up: 522.01 +/- 521.86 ng/ml, n = 8; Mean +/- SD, p < 0.003) and MARE (no MARE: 112.08 +/- 302.00ng/ml, n = 298; MARE: 506.16 +/- 624.61 ng/ml, n = 16, Mean +/- SD, p < 0.001) during the follow-up of 90 days after contrast media exposure. Correction of urine VDBP concentrations for creatinine excretion confirmed its predictive value and was consistent with increased levels of urinary Kidney Injury Molecule1 (KIM-1) and baseline plasma creatinine in patients with above mentioned complications. The impact of urinary VDBP and KIM-1 on MARE was independent of known CIN risk factors such as anemia, preexisting renal failure, preexisting heart failure, and diabetes. Conclusions Urinary VDBP is a promising novel biomarker of major contrast induced nephropathy-associated events 90 days after contrast media exposure.
Between the beginning of its full-scale scientific operations in 2007 and 2012, the VERITAS Cherenkov telescope array observed more than 130 blazars; of these, 26 were detected as very-high-energy (VHE; E > 100 GeV) gamma-ray sources. In this work, we present the analysis results of a sample of 114 undetected objects. The observations constitute a total live-time of similar to 570 hr. The sample includes several unidentified Fermi-Large Area Telescope (LAT) sources (located at high Galactic latitude) as well as all the sources from the second Fermi-LAT catalog that are contained within the field of view of the VERITAS observations. We have also performed optical spectroscopy measurements in order to estimate the redshift of some of these blazars that do not have spectroscopic distance estimates. We present new optical spectra from the Kast instrument on the Shane telescope at the Lick observatory for 18 blazars included in this work, which allowed for the successful measurement or constraint on the redshift of four of them. For each of the blazars included in our sample, we provide the flux upper limit in the VERITAS energy band. We also study the properties of the significance distributions and we present the result of a stacked analysis of the data set, which shows a 4s excess.
In the context of an increasing population of aging people and a shift of medical paradigm towards an individualized medicine in health care, nanostructured lanthanides doped sodium yttrium fluoride (NaYF4) represents an exciting class of upconversion nanomaterials (UCNM) which are suitable to bring forward developments in biomedicine and -biodetection. Despite the fact that among various fluoride based upconversion (UC) phosphors lanthanide doped NaYF4 is one of the most studied upconversion nanomaterial, many open questions are still remaining concerning the interplay of the population routes of sensitizer and activator electronic states involved in different luminescence upconversion photophysics as well as the role of phonon coupling. The collective work aims to explore a detailed understanding of the upconversion mechanism in nanoscaled NaYF4 based materials co-doped with several lanthanides, e.g. Yb3+ and Er3+ as the "standard" type upconversion nanoparticles (UCNP) up to advanced UCNP with Gd3+ and Nd3+. Especially the impact of the crystal lattice structure as well as the resulting lattice phonons on the upconversion luminescence was investigated in detail based on different mixtures of cubic and hexagonal NaYF4 nanoscaled crystals. Three synthesis methods, depending on the attempt of the respective central spectroscopic questions, could be accomplished in the following work. NaYF4 based upconversion nanoparticles doped with several combination of lanthanides (Yb3+, Er3+, Gd3+ and Nd3+) were synthesized successfully using a hydrothermal synthesis method under mild conditions as well as a co-precipitation and a high temperature co-precipitation technique. Structural information were gathered by means of X-ray diffraction (XRD), electron microscopy (TEM), dynamic light scattering (DLS), Raman spectroscopy and inductively coupled plasma atomic emission spectrometry (ICP-OES). The results were discussed in detail with relation to the spectroscopic results. A variable spectroscopic setup was developed for multi parameter upconversion luminescence studies at various temperature 4 K to 328 K. Especially, the study of the thermal behavior of upconversion luminescence as well as time resolved area normalized emission spectra were a prerequisite for the detailed understanding of intramolecular deactivation processes, structural changes upon annealing or Gd3+ concentration, and the role of phonon coupling for the upconversion efficiency. Subsequently it became possible to synthesize UCNP with tailored upconversion luminescence properties. In the end, the potential of UCNP for life science application should be enunciated in context of current needs and improvements of a nanomaterial based optical sensors, whereas the "standard" UCNP design was attuned according to the special conditions in the biological matrix. In terms of a better biocompatibility due to a lower impact on biological tissue and higher penetrability for the excitation light. The first step into this direction was to use Nd3+ ions as a new sensitizer in tridoped NaYF4 based UCNP, whereas the achieved absolute and relative temperature sensitivity is comparable to other types of local temperature sensors in the literature.
When does a diffusing particle reach its target for the first time? This first-passage time (FPT) problem is central to the kinetics of molecular reactions in chemistry and molecular biology. Here, we explain the behavior of smooth FPT densities, for which all moments are finite, and demonstrate universal yet generally non-Poissonian long-time asymptotics for a broad variety of transport processes. While Poisson-like asymptotics arise generically in the presence of an effective repulsion in the immediate vicinity of the target, a time-scale separation between direct and reflected indirect trajectories gives rise to a universal proximity effect: Direct paths, heading more or less straight from the point of release to the target, become typical and focused, with a narrow spread of the corresponding first-passage times. Conversely, statistically dominant indirect paths exploring the entire system tend to be massively dissimilar. The initial distance to the target particularly impacts gene regulatory or competitive stochastic processes, for which few binding events often determine the regulatory outcome. The proximity effect is independent of details of the transport, highlighting the robust character of the FPT features uncovered here.
Do properties of individual languages shape the mechanisms by which they are processed? By virtue of their non-concatenative morphological structure, the recognition of complex words in Semitic languages has been argued to rely strongly on morphological information and on decomposition into root and pattern constituents. Here, we report results from a masked priming experiment in Hebrew in which we contrasted verb forms belonging to two morphological classes, Paal and Piel, which display similar properties, but crucially differ on whether they are extended to novel verbs. Verbs from the open-class Piel elicited familiar root priming effects, but verbs from the closed-class Paal did not. Our findings indicate that, similarly to other (e.g., Indo-European) languages, down-to-the-root decomposition in Hebrew does not apply to stems of non-productive verbal classes. We conclude that the Semitic word processor is less unique than previously thought: Although it operates on morphological units that are combined in a non-linear way, it engages the same universal mechanisms of storage and computation as those seen in other languages.
Do properties of individual languages shape the mechanisms by which they are processed? By virtue of their nonconcatenative
morphological structure, the recognition of complex words in Semitic languages has been argued to rely
strongly on morphological information and on decomposition into root and pattern constituents. Here, we report results
from a masked priming experiment in Hebrew in which we contrasted verb forms belonging to two morphological
classes, Paal and Piel, which display similar properties, but crucially differ on whether they are extended to novel verbs.
Verbs from the open-class Piel elicited familiar root priming effects, but verbs from the closed-class Paal did not. Our
findings indicate that, similarly to other (e.g., Indo-European) languages, down-to-the-root decomposition in Hebrew
does not apply to stems of non-productive verbal classes. We conclude that the Semitic word processor is less unique
than previously thought: Although it operates on morphological units that are combined in a non-linear way, it engages
the same universal mechanisms of storage and computation as those seen in other languages.
Background: Deception can distort psychological tests on socially sensitive topics. Understanding the cerebral processes that are involved in such faking can be useful in detection and prevention of deception. Previous research shows that faking a brief implicit association test (BIAT) evokes a characteristic ERP response. It is not yet known whether temporarily available self-control resources moderate this response. We randomly assigned 22 participants (15 females, 24.23 +/- 2.91 years old) to a counterbalanced repeated-measurements design. Participants first completed a Brief-IAT (BIAT) on doping attitudes as a baseline measure and were then instructed to fake a negative doping attitude both when self-control resources were depleted and non-depleted. Cerebral activity during BIAT performance was assessed using high-density EEG. Conclusions: Results indicate that temporarily available self-control resources do not affect overt faking success on a BIAT. However, differences were found on an electrophysiological level. This indicates that while on a phenotypical level self-control resources play a negligible role in deliberate test faking the underlying cerebral processes are markedly different.
Background:
Deception can distort psychological tests on socially sensitive topics. Understanding the cerebral
processes that are involved in such faking can be useful in detection and prevention of deception. Previous research
shows that faking a brief implicit association test (BIAT ) evokes a characteristic ERP response. It is not yet known
whether temporarily available self-control resources moderate this response. We randomly assigned 22 participants
(15 females, 24.23
±
2.91
years old) to a counterbalanced repeated-measurements design. Participants first com-
pleted a Brief-IAT (BIAT ) on doping attitudes as a baseline measure and were then instructed to fake a negative dop
-
ing attitude both when self-control resources were depleted and non-depleted. Cerebral activity during BIAT perfor
-
mance was assessed using high-density EEG.
Results:
Compared to the baseline BIAT, event-related potentials showed a first interaction at the parietal P1,
while significant post hoc differences were found only at the later occurring late positive potential. Here, signifi-
cantly decreased amplitudes were recorded for ‘normal’ faking, but not in the depletion condition. In source space,
enhanced activity was found for ‘normal’ faking in the bilateral temporoparietal junction. Behaviorally, participants
were successful in faking the BIAT successfully in both conditions.
Conclusions:
Results indicate that temporarily available self-control resources do not affect overt faking success on
a BIAT. However, differences were found on an electrophysiological level. This indicates that while on a phenotypical
level self-control resources play a negligible role in deliberate test faking the underlying cerebral processes are markedly different.
Swets et al. (2008. Underspecification of syntactic ambiguities: Evidence from self-paced reading. Memory and Cognition, 36(1), 201–216) presented evidence that the so-called ambiguity advantage [Traxler et al. (1998 Traxler, M. J., Pickering, M. J., & Clifton, C. (1998). Adjunct attachment is not a form of lexical ambiguity resolution. Journal of Memory and Language, 39(4), 558–592. doi: 10.1006/jmla.1998.2600[CrossRef], [Web of Science ®], [Google Scholar]). Adjunct attachment is not a form of lexical ambiguity resolution. Journal of Memory and Language, 39(4), 558–592], which has been explained in terms of the Unrestricted Race Model, can equally well be explained by assuming underspecification in ambiguous conditions driven by task-demands. Specifically, if comprehension questions require that ambiguities be resolved, the parser tends to make an attachment: when questions are about superficial aspects of the target sentence, readers tend to pursue an underspecification strategy. It is reasonable to assume that individual differences in strategy will play a significant role in the application of such strategies, so that studying average behaviour may not be informative. In order to study the predictions of the good-enough processing theory, we implemented two versions of underspecification: the partial specification model (PSM), which is an implementation of the Swets et al. proposal, and a more parsimonious version, the non-specification model (NSM). We evaluate the relative fit of these two kinds of underspecification to Swets et al.’s data; as a baseline, we also fitted three models that assume no underspecification. We find that a model without underspecification provides a somewhat better fit than both underspecification models, while the NSM model provides a better fit than the PSM. We interpret the results as lack of unambiguous evidence in favour of underspecification; however, given that there is considerable existing evidence for good-enough processing in the literature, it is reasonable to assume that some underspecification might occur. Under this assumption, the results can be interpreted as tentative evidence for NSM over PSM. More generally, our work provides a method for choosing between models of real-time processes in sentence comprehension that make qualitative predictions about the relationship between several dependent variables. We believe that sentence processing research will greatly benefit from a wider use of such methods.
Swets et al. (2008. Underspecification of syntactic ambiguities: Evidence from self-paced reading. Memory and Cognition, 36(1), 201–216) presented evidence that the so-called ambiguity advantage [Traxler et al. (1998). Adjunct attachment is not a form of lexical ambiguity resolution. Journal of Memory and Language, 39(4), 558–592], which has been explained in terms of the Unrestricted Race Model, can equally well be explained by assuming underspecification in ambiguous conditions driven by task-demands. Specifically, if comprehension questions require that ambiguities be resolved, the parser tends to make an attachment: when questions are about superficial aspects of the target sentence, readers tend to pursue an underspecification strategy. It is reasonable to assume that individual differences in strategy will play a significant role in the application of such strategies, so that studying average behaviour may not be informative. In order to study the predictions of the good-enough processing theory, we implemented two versions of underspecification: the partial specification model (PSM), which is an implementation of the Swets et al. proposal, and a more parsimonious version, the non-specification model (NSM). We evaluate the relative fit of these two kinds of underspecification to Swets et al.’s data; as a baseline, we also fitted three models that assume no underspecification. We find that a model without underspecification provides a somewhat better fit than both underspecification models, while the NSM model provides a better fit than the PSM. We interpret the results as lack of unambiguous evidence in favour of underspecification; however, given that there is considerable existing evidence for good-enough processing in the literature, it is reasonable to assume that some underspecification might occur. Under this assumption, the results can be interpreted as tentative evidence for NSM over PSM. More generally, our work provides a method for choosing between models of real-time processes in sentence comprehension that make qualitative predictions about the relationship between several dependent variables. We believe that sentence processing research will greatly benefit from a wider use of such methods.
Understanding the rates and processes of denudation is key to unraveling the dynamic processes that shape active orogens. This includes decoding the roles of tectonic and climate-driven processes in the long-term evolution of high- mountain landscapes in regions with pronounced tectonic activity and steep climatic and surface-process gradients. Well-constrained denudation rates can be used to address a wide range of geologic problems. In steady-state landscapes, denudation rates are argued to be proportional to tectonic or isostatic uplift rates and provide valuable insight into the tectonic regimes underlying surface denudation. The use of denudation rates based on terrestrial cosmogenic nuclide (TCN) such as 10Beryllium has become a widely-used method to quantify catchment-mean denudation rates. Because such measurements are averaged over timescales of 102 to 105 years, they are not as susceptible to stochastic changes as shorter-term denudation rate estimates (e.g., from suspended sediment measurements) and are therefore considered more reliable for a comparison to long-term processes that operate on geologic timescales. However, the impact of various climatic, biotic, and surface processes on 10Be concentrations and the resultant denudation rates remains unclear and is subject to ongoing discussion. In this thesis, I explore the interaction of climate, the biosphere, topography, and geology in forcing and modulating denudation rates on catchment to orogen scales.
There are many processes in highly dynamic active orogens that may effect 10Be concentrations in modern river sands and therefore impact 10Be-derived denudation rates. The calculation of denudation rates from 10Be concentrations, however, requires a suite of simplifying assumptions that may not be valid or applicable in many orogens. I investigate how these processes affect 10Be concentrations in the Arun Valley of Eastern Nepal using 34 new 10Be measurements from the main stem Arun River and its tributaries. The Arun Valley is characterized by steep gradients in climate and topography, with elevations ranging from <100 m asl in the foreland basin to >8,000 asl in the high sectors to the north. This is coupled with a five-fold increase in mean annual rainfall across strike of the orogen. Denudation rates from tributary samples increase toward the core of the orogen, from <0.2 to >5 mm/yr from the Lesser to Higher Himalaya. Very high denudation rates (>2 mm/yr), however, are likely the result of 10Be TCN dilution by surface and climatic processes, such as large landsliding and glaciation, and thus may not be representative of long-term denudation rates. Mainstem Arun denudation rates increase downstream from ~0.2 mm/yr at the border with Tibet to 0.91 mm/yr at its outlet into the Sapt Kosi. However, the downstream 10Be concentrations may not be representative of the entire upstream catchment. Instead, I document evidence for downstream fining of grains from the Tibetan Plateau, resulting in an order-of-magnitude apparent decrease in the measured 10Be concentration.
In the Arun Valley and across the Himalaya, topography, climate, and vegetation are strongly interrelated. The observed increase in denudation rates at the transition from the Lesser to Higher Himalaya corresponds to abrupt increases in elevation, hillslope gradient, and mean annual rainfall. Thus, across strike (N-S), it is difficult to decipher the potential impacts of climate and vegetation cover on denudation rates. To further evaluate these relationships I instead took advantage of an along-strike west-to-east increase of mean annual rainfall and vegetation density in the Himalaya. An analysis of 136 published 10Be denudation rates from along strike of the revealed that median denudation rates do not vary considerably along strike of the Himalaya, ~1500 km E-W. However, the range of denudation rates generally decreases from west to east, with more variable denudation rates in the northwestern regions of the orogen than in the eastern regions. This denudation rate variability decreases as vegetation density increases (R=- 0.90), and increases proportionately to the annual seasonality of vegetation (R=0.99). Moreover, rainfall and vegetation modulate the relationship between topographic steepness and denudation rates such that in the wet, densely vegetated regions of the Himalaya, topography responds more linearly to changes in denudation rates than in dry, sparsely vegetated regions, where the response of topographic steepness to denudation rates is highly nonlinear. Understanding the relationships between denudation rates, topography, and climate is also critical for interpreting sedimentary archives. However, there is a lack of understanding of how terrestrial organic matter is transported out of orogens and into sedimentary archives. Plant wax lipid biomarkers derived from terrestrial and marine sedimentary records are commonly used as paleo- hydrologic proxy to help elucidate these problems. I address the issue of how to interpret the biomarker record by using the plant wax isotopic composition of modern suspended and riverbank organic matter to identify and quantify organic matter source regions in the Arun Valley. Topographic and geomorphic analysis, provided by the 10Be catchment-mean denudation rates, reveals that a combination of topographic steepness (as a proxy for denudation) and vegetation density is required to capture organic matter sourcing in the Arun River.
My studies highlight the importance of a rigorous and careful interpretation of denudation rates in tectonically active orogens that are furthermore characterized by strong climatic and biotic gradients. Unambiguous information about these issues is critical for correctly decoding and interpreting the possible tectonic and climatic forces that drive erosion and denudation, and the manifestation of the erosion products in sedimentary archives.
Underdamped scaled Brownian motion: (non-)existence of the overdamped limit in anomalous diffusion
(2016)
It is quite generally assumed that the overdamped Langevin equation provides a quantitative description of the dynamics of a classical Brownian particle in the long time limit. We establish and investigate a paradigm anomalous diffusion process governed by an underdamped Langevin equation with an explicit time dependence of the system temperature and thus the diffusion and damping coefficients. We show that for this underdamped scaled Brownian motion (UDSBM) the overdamped limit fails to describe the long time behaviour of the system and may practically even not exist at all for a certain range of the parameter values. Thus persistent inertial effects play a non-negligible role even at significantly long times. From this study a general questions on the applicability of the overdamped limit to describe the long time motion of an anomalously diffusing particle arises, with profound consequences for the relevance of overdamped anomalous diffusion models. We elucidate our results in view of analytical and simulations results for the anomalous diffusion of particles in free cooling granular gases.
It is quite generally assumed that the overdamped Langevin equation provides a quantitative description of the dynamics of a classical Brownian particle in the long time limit. We establish and investigate a paradigm anomalous diffusion process governed by an underdamped Langevin equation with an explicit time dependence of the system temperature and thus the diffusion and damping coefficients. We show that for this underdamped scaled Brownian motion (UDSBM) the overdamped limit fails to describe the long time behaviour of the system and may practically even not exist at all for a certain range of the parameter values. Thus persistent inertial effects play a non-negligible role even at significantly long times. From this study a general questions on the applicability of the overdamped limit to describe the long time motion of an anomalously diffusing particle arises, with profound consequences for the relevance of overdamped anomalous diffusion models. We elucidate our results in view of analytical and simulations results for the anomalous diffusion of particles in free cooling granular gases.
It is quite generally assumed that the overdamped Langevin equation provides a quantitative description of the dynamics of a classical Brownian particle in the long time limit. We establish and investigate a paradigm anomalous diffusion process governed by an underdamped Langevin equation with an explicit time dependence of the system temperature and thus the diffusion and damping coefficients. We show that for this underdamped scaled Brownian motion (UDSBM) the overdamped limit fails to describe the long time behaviour of the system and may practically even not exist at all for a certain range of the parameter values. Thus persistent inertial effects play a non-negligible role even at significantly long times. From this study a general questions on the applicability of the overdamped limit to describe the long time motion of an anomalously diffusing particle arises, with profound consequences for the relevance of overdamped anomalous diffusion models. We elucidate our results in view of analytical and simulations results for the anomalous diffusion of particles in free cooling granular gases.
Uncovering the acoustic vowel space of a previously undescribed language: The vowels of Nambo
(2016)
This study presents the first acoustic description of the vowel space of a Papuan language—Nambo, spoken in southern Papua New Guinea—based on duration and first and second formant measurements from 19 adult male and female speakers across three age groups (young, middle-aged, senior). Phonemically, Nambo has six full vowels /i, e, æ, ɑ, o, u/ and a reduced vowel tentatively labeled /ə/. Unlike the full vowels, the quality of /ə/ showed great variation: seniors' and young females' realizations tended to be more open and retracted than those by young males, while middle-aged speakers' productions fell between these two variants.
Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
Himalayan water resources attract a rapidly growing number of hydroelectric power projects (HPP) to satisfy Asia's soaring energy demands. Yet HPP operating or planned in steep, glacier-fed mountain rivers face hazards of glacial lake outburst floods (GLOFs) that can damage hydropower infrastructure, alter water and sediment yields, and compromise livelihoods downstream. Detailed appraisals of such GLOF hazards are limited to case studies, however, and a more comprehensive, systematic analysis remains elusive. To this end we estimate the regional exposure of 257 Himalayan HPP to GLOFs, using a flood-wave propagation model fed by Monte Carlo-derived outburst volumes of >2300 glacial lakes. We interpret the spread of thus modeled peak discharges as a predictive uncertainty that arises mainly from outburst volumes and dam-breach rates that are difficult to assess before dams fail. With 66% of sampled HPP are on potential GLOF tracks, up to one third of these HPP could experience GLOF discharges well above local design floods, as hydropower development continues to seek higher sites closer to glacial lakes. We compute that this systematic push of HPP into headwaters effectively doubles the uncertainty about GLOF peak discharge in these locations. Peak discharges farther downstream, in contrast, are easier to predict because GLOF waves attenuate rapidly. Considering this systematic pattern of regional GLOF exposure might aid the site selection of future Himalayan HPP. Our method can augment, and help to regularly update, current hazard assessments, given that global warming is likely changing the number and size of Himalayan meltwater lakes.
Inspired by the application of ultrasonic cavitation based mechanical force (CMF) to open small channels in natural soft materials (skin or tissue), it is explored whether an artificial polymer network can be created, in which shape-changes can be induced by CMF. This concept comprises an interconnected macroporous rhodium-phosphine (Rh-P) coordination polymer network, in which a CMF can reversibly dissociate the Rh-P microphases. In this way, the ligand exchange of Rh-P coordination bonds in the polymer network is accelerated, resulting in a topological rearrangement of molecular switches. This rearrangement of molecular switches enables the polymer network to release internal tension under ultrasound exposure, resulting in a CMF-induced shape-memory capability. The interconnected macroporous structure with thin pore walls is essential for allowing the CMF to effectively permeate throughout the polymer network. Potential applications of this CMF-induced shape-memory polymer can be mechanosensors or ultrasound controlled switches.
The molecular ability to selectively and efficiently convert sunlight into other forms of energy like heat, bond change, or charge separation is truly remarkable. The decisive steps in these transformations often happen on a femtosecond timescale and require transitions among different electronic states that violate the Born-Oppenheimer approximation (BOA). Non-BOA transitions pose challenges to both theory and experiment. From a theoretical point of view, excited state dynamics and nonadiabatic transitions both are difficult problems (see Figure 1(a)). However, the theory on non-BOA dynamics has advanced significantly over the last two decades. Full dynamical simulations for molecules of the size of nucleobases have been possible for a couple of years and allow predictions of experimental observables like photoelectron energy or ion yield. The availability of these calculations for isolated molecules has spurred new experimental efforts to develop methods that are sufficiently different from all optical techniques. For determination of transient molecular structure, femtosecond X-ray diffraction and electron diffraction have been implemented on optically excited molecules.
In this thesis, the two prototype catalysts Fe(CO)₅ and Cr(CO)₆ are investigated with time-resolved photoelectron spectroscopy at a high harmonic setup. In both of these metal carbonyls, a UV photon can induce the dissociation of one or more ligands of the complex. The mechanism of the dissociation has been debated over the last decades. The electronic dynamics of the first dissociation occur on the femtosecond timescale.
For the experiment, an existing high harmonic setup was moved to a new location, was extended, and characterized. The modified setup can induce dynamics in gas phase samples with photon energies of 1.55eV, 3.10eV, and 4.65eV. The valence electronic structure of the samples can be probed with photon energies between 20eV and 40eV. The temporal resolution is 111fs to 262fs, depending on the combination of the two photon energies.
The electronically excited intermediates of the two complexes, as well as of the reaction product Fe(CO)₄, could be observed with photoelectron spectroscopy in the gas phase for the first time. However, photoelectron spectroscopy gives access only to the final ionic states. Corresponding calculations to simulate these spectra are still in development. The peak energies and their evolution in time with respect to the initiation pump pulse have been determined, these peaks have been assigned based on literature data. The spectra of the two complexes show clear differences. The dynamics have been interpreted with the assumption that the motion of peaks in the spectra relates to the movement of the wave packet in the multidimensional energy landscape. The results largely confirm existing models for the reaction pathways. In both metal carbonyls, this pathway involves a direct excitation of the wave packet to a metal-to-ligand charge transfer state and the subsequent crossing to a dissociative ligand field state. The coupling of the electronic dynamics to the nuclear dynamics could explain the slower dissociation in Fe(CO)₅ as compared to Cr(CO)₆.
Udmurt as an OV language
(2016)
This is the first study to investigate Hubert Haider's (2000, 2010, 2013, 2014) proposed systematic differences between OV and VO language in a family other than Germanic. Its aim is to gather evidence on whether basic word order is predictive of further properties of a language. The languages under investigation are the Finno-Ugric languages Udmurt (as an OV language) and Finnish (as a VO language). Counter to Kayne (1994), Haider proposes that the structure of a sentence with a head-final VP is fundamentally different from that of a sentence with a head-initial VP, e.g., OV languages do not exhibit a VP-shell structure, and they do not employ a TP layer with a structural subject position. Haider's proposed structural differences are said to result in the following empirically testable differences:
(a) VP: the availability of VP-internal adverbial intervention and scrambling only in OV-VPs;
(b) subjects: the lack of certain subject-object asymmetries in OV languages, i.e., lack of the subject condition and lack of superiority effects;
(c) V-complexes: the availability of partial predicate fronting only in OV languages; different orderings between selecting and selected verbs; the intervention of non-verbal material between verbs only in VO languages;
(d) V-particles: differences in the distribution of resultative phrases and verb particles.
Udmurt and Finnish behave in line with Haider's predictions with regard to the status of the subject, with regard to the order of selecting and selected verbs, and with regard to the availability of partial predicate fronting. Moreover, Udmurt allows for adverbial intervention and scrambling, as predicted, whereas the status of these properties in Finnish could not be reliably determined due to obligatory V-to-T. There is also counterevidence to Haider's predictions: Udmurt allows for non-verbal material between verbs, and the distribution of resultative phrases and verb particles is essentially as free as the distribution of adverbial phrases in both Finno-Ugric languages. As such, Haider's theory is not falsified by the data from Udmurt and Finnish (except for his theory on verb particles), but it is also not fully supported by the data.
The advantages of remote sensing using Unmanned Aerial Vehicles (UAVs) are a high spatial resolution of images, temporal flexibility and narrow-band spectral data from different wavelengths domains. This enables the detection of spatio-temporal dynamics of environmental variables, like plant-related carbon dynamics in agricultural landscapes. In this paper, we quantify spatial patterns of fresh phytomass and related carbon (C) export using imagery captured by a 12-band multispectral camera mounted on the fixed wing UAV Carolo P360. The study was performed in 2014 at the experimental area CarboZALF-D in NE Germany. From radiometrically corrected and calibrated images of lucerne (Medicago sativa), the performance of four commonly used vegetation indices (VIs) was tested using band combinations of six near-infrared bands. The highest correlation between ground-based measurements of fresh phytomass of lucerne and VIs was obtained for the Enhanced Vegetation Index (EVI) using near-infrared band b(899). The resulting map was transformed into dry phytomass and finally upscaled to total C export by harvest. The observed spatial variability at field- and plot-scale could be attributed to small-scale soil heterogeneity in part.