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Androgen receptors are expressed in the kidney and serum testosterone is negatively associated with serum phosphate in males, suggesting a role of testosterone in renal phosphate handling. In this cross‐sectional study, we examined the association of serum total and free testosterone with acute phosphate and calcium excretion in males in response to an oral phosphate challenge. Thirty‐five healthy adult males with normal baseline testosterone levels consumed a 500 mg phosphorus drink and the urinary excretion of minerals, as well as levels of relevant circulating parameters, were assessed at baseline and hourly for 4 h. Serum total testosterone was positively associated with overall phosphate excretion (r = 0.35, p = 0.04) and calcium excretion (r = 0.44, p = 0.00) in response to the challenge. Serum free testosterone was positively associated with post‐challenge calcium excretion (r = 0.34, p = 0.048), but significance was not reached for phosphate excretion (r = 0.31, p = 0.07). Serum total and free testosterone were not associated with parathyroid hormone, fibroblast growth factor‐23, or vitamin D—key factors implicated in phosphate and calcium regulation. Overall, higher serum total testosterone levels in healthy middle‐aged males are associated with a greater capacity to acutely excrete phosphate and calcium after a single oral phosphate challenge, suggesting potential ramifications of testosterone deficiency related to mineral homeostasis. [ABSTRACT FROM AUTHOR]

The world's forests are being increasingly disturbed from exposure to the compounding impacts of land use and climate change, in addition to natural disturbance regimes. Boreal forests have a lower level of deforestation compared to tropical forests, and while they have higher levels of natural disturbances, the accumulated impact of forest management for commodity production coupled with worsening fire weather conditions and other climate-related stressors is resulting in ecosystem degradation and loss of biodiversity. We used satellite-based time-series analysis of two canopy indices—canopy photosynthesis and canopy water stress—to calculate an index that maps the relative stability of forest canopies in the Canadian provinces of Ontario and Quebec. By drawing upon available spatial time-series data on logging, wildfire, and insect infestation impacts, we were able to attribute the causal determinants of areas identified as having unstable forest canopy. The slope of the two indices that comprise the stability index also provided information as to where the forest is recovering from prior disturbances. The stability analyses and associated spatial datasets are available in an interactive web-based mapping app. that can be used to map disturbed forest canopies and the attribution of disturbances to human or natural causes. This information can assist decision-makers in identifying areas that are potentially ecologically degraded and in need of restoration and those stable areas that are a priority for protection. [ABSTRACT FROM AUTHOR]

Context. Species connectivity mapping is a technically challenging task for conservation practitioners and nongovernment organisations to undertake as it requires experience in geographic information systems and often some computer programming. Aims. We developed a decision support tool to provide spatial information and data on potential habitat connectivity and optimum connectivity pathways for a selection of forest-dependent vertebrate fauna in eastern and south-western Australia. Methods. We systematically searched spatial data repositories for Australian spatial datasets for modelling connectivity. A least cost paths and patch connectivity approach was used to map potential habitat connectivity for (1) a single species - the glossy black cockatoo (Calyptorhynchus lathami) of South East Queensland, and (2) four species guilds - rainforest pigeons, gliding possums, the black cockatoos of south-western Western Australia and a landscape level forest connectivity. Optimum connectivity pathways were assessed for protection status. Key results. In total 71 spatial datasets useful for habitat connectivity mapping were identified. Species and guild modelling found that the protection status for optimum connectivity pathways varied between 24.7% and 53.3%. A decision support mapping tool was then created to enable users to interactively explore the connectivity data and download the spatial datasets for further analysis. Conclusions. The development of a decision support tool for mapping habitat connectivity in eastern and south-western Australia represents a useful platform for conservation practitioners as it provides valuable spatial information on potential connectivity pathways for forest-dependent vertebrate fauna. Implications. The tool can aid in the prioritisation of conservation actions aimed at enhancing habitat connectivity and mitigating the impacts of habitat fragmentation on biodiversity in the two regions. [ABSTRACT FROM AUTHOR]

The Cox regression model or accelerated failure time regression models are often used for describing the relationship between survival outcomes and potential explanatory variables. These models assume the studied covariates are connected to the survival time or its distribution or their transformations through a function of a linear regression form. In this article, we propose nonparametric, nonlinear algorithms (deepAFT methods) based on deep artificial neural networks to model survival outcome data in the broad distribution family of accelerated failure time models. The proposed methods predict survival outcomes directly and tackle the problem of censoring via an imputation algorithm as well as re‐weighting and transformation techniques based on the inverse probabilities of censoring. Through extensive simulation studies, we confirm that the proposed deepAFT methods achieve accurate predictions. They outperform the existing regression models in prediction accuracy, while being flexible and robust in modeling covariate effects of various nonlinear forms. Their prediction performance is comparable to other established deep learning methods such as deepSurv and random survival forest methods. Even though the direct output is the expected survival time, the proposed AFT methods also provide predictions for distributional functions such as the cumulative hazard and survival functions without additional learning efforts. For situations where the popular Cox regression model may not be appropriate, the deepAFT methods provide useful and effective alternatives, as shown in simulations, and demonstrated in applications to a lymphoma clinical trial study. [ABSTRACT FROM AUTHOR]

We present an implementation for the calculation of molecular response properties using the algebraic-diagrammatic construction (ADC)/intermediate state representation approach. For the second-order ADC model [ADC(2)], a memory-efficient ansatz avoiding the storage of double excitation amplitudes is investigated. We compare the performance of different numerical algorithms for the solution of the underlying response equations for ADC(2) and show that our approach also strongly improves the convergence behavior for the investigated algorithms compared with the standard implementation. All routines are implemented in an open-source Python library. [ABSTRACT FROM AUTHOR]

Purpose: Frailty is common in critically ill patients but the timing and optimal method of frailty ascertainment, trajectory and relationship with care processes remain uncertain. We sought to elucidate the trajectory and care processes of frailty in critically ill patients as measured by the Clinical Frailty Scale (CFS) and Frailty Index (FI). Methods: This is a multi-centre prospective cohort study enrolling patients ≥ 50 years old receiving life support > 24 h. Frailty severity was assessed with a CFS, and a FI based on the elements of a comprehensive geriatric assessment (CGA) at intensive care unit (ICU) admission, hospital discharge and 6 months. For the primary outcome of frailty prevalence, it was a priori dichotomously defined as a CFS ≥ 5 or FI ≥ 0.2. Processes of care, adverse events were collected during ICU and ward stays while outcomes were determined for ICU, hospital, and 6 months. Results: In 687 patients, whose age (mean ± standard deviation) was 68.8 ± 9.2 years, frailty prevalence was higher when measured with the FI (CFS, FI %): ICU admission (29.8, 44.8), hospital discharge (54.6, 67.9), 6 months (34.1, 42.6). Compared to ICU admission, aggregate frailty severity increased to hospital discharge but improved by 6 months; individually, CFS and FI were higher in 45.3% and 50.6% patients, respectively at 6 months. Compared to hospital discharge, 18.7% (CFS) and 20% (FI) were higher at 6 months. Mortality was higher in frail patients. Processes of care and adverse events were similar except for worse ICU/ward mobility and more frequent delirium in frail patients. Conclusions: Frailty severity was dynamic, can be measured during recovery from critical illness using the CFS and FI which were both associated with worse outcomes. Although the CFS is a global measure, a CGA FI based may have advantages of being able to measure frailty levels, identify deficits, and potential targets for intervention. [ABSTRACT FROM AUTHOR]

Introduction: Vitamin D insufficiency is common in patients who receive hemodialysis, yet there is no clear guidance regarding surveillance or treatment. We hypothesized that increasing 25(OH)D3 levels is associated with lower phosphate, parathyroid hormone (PTH), and alkaline phosphatase (ALP). Methods: Baseline 25(OH)D3 level was measured in all patients receiving in-center hemodialysis in June 2017. Laboratory parameters were measured every 6 (phosphate, calcium) or 12 weeks (25(OH)D3, PTH, ALP) until February 2021. In September 2018, a treatment algorithm of 50,000 IU weekly until sufficient followed by 50,000 IU monthly was suggested. Generalized linear mixed regression models including linear spline effects, a log link function, and random effects were used to examine the impact of increasing 25(OH)D3 levels on calcium, phosphate, ALP, and PTH. Results: Of 697 participants, 15% and 57% had vitamin D deficiency (25(OH)D3 <25 nmol/L) and insufficiency (between 25 and 74 nmol/L). Incorporating up to 7,272 observations, increasing 25(OH)D3 was associated with significantly decreasing PTH for 25(OH)D3 levels between 25 and 75 nmol/L regardless of vitamin D treatment. In an interaction model, the negative slope between 25(OH)D3 and PTH remained significant beyond 75 nmol/L in the absence of calcitriol. Increasing 25(OH)D3 was associated with significantly decreasing phosphate for 25(OH)D3 levels between 25 and 75 nmol/L regardless of vitamin D treatment and below 25 nmol/L in values of untreated patients. Calcium increased across the spectrum of 25(OH)D3 regardless of vitamin D treatment. Overall, 0.2% of 25(OH)D3 levels exceeded 250 nmol/L and 2.1% of calcium levels exceeded the normal range. Conclusions: Vitamin D treatment in a real-world setting was safe and associated with lower PTH levels. Whether improved biochemical markers translate to a reduction in clinical endpoints warrants further study. [ABSTRACT FROM AUTHOR]

Context: The southern and central greater glider (Petauroides volans) is a nationally listed endangered species in Australia. The species depends upon mature native forest providing critical habitat resources including tree hollows. Aims: This study aimed to map and evaluate the tenure of patches of potential high-quality (core) habitat and corridors for the southern greater glider in Queensland. Methods: Within greater glider habitat, we mapped 10 ranked classes of relative forest maturity using a model comprising remotely sensed metrics of canopy height, above-ground living biomass and canopy cover at a 30 m resolution. We also modelled the optimum movement corridors within and between habitat patches. Key results: Results showed that 35% (4.943 million ha) of habitat was found in the more mature classes (Classes 7–9), which represent a proxy for associated limiting habitat resources, especially tree hollows. Mean patch size above a 1.6 ha threshold was found to be 122 ha and most patches (71%) were ≤10 ha, with 14 patches ≥100 000 ha. Freehold and leasehold lands hold 63.4% of the more mature habitat, multiple-use public forest 21.4% and nature conservation areas 12.8%. About half of the potential habitat is located on formally recognised Indigenous lands that represent different categories of Aboriginal ownership, management and other special rights. Conclusions: The protection of mature forest patches and movement corridors is necessary for the conservation of the greater glider, a nationally listed threatened species. Implications: Conservation interventions are needed, using a whole-of-landscape approach to protect core habitat and corridors from inappropriate land use. With increasing pressures on Australian forests, identifying old growth and mature habitats for threatened species is vital. We evaluated greater glider habitats and found that mature areas are vulnerable to human impacts. Protecting areas containing mature forests and hollow-bearing trees is crucial for the species' survival. [ABSTRACT FROM AUTHOR]

The Canadian boreal forest biome has been subjected to a long history of management for wood production. Here, we examined the cumulative impacts of logging on older forests in terms of area, distribution and patch configuration in the managed forest zones of the Eastern Canadian provinces of Ontario and Quebec. We also examined the consequences of these cumulative impacts on a once widely distributed and now threatened species, the woodland caribou (Rangifer tarandus caribou). The cumulative area of recently logged forest (since ~1976) was 14,024,619 ha, with 8,210,617 ha in Quebec and 5,814,002 ha in Ontario. The total area of older forests was 21,249,341 ha, with 11,840,474 ha in Quebec and 9,408,867 ha in Ontario. Patch statistics revealed that there were 1,085,822 older forests with core patches < 0.25 ha and an additional 603,052 < 1.0 ha. There were 52 > 10,00–50,000 ha and 8 < 50,000 ha. Older forest patches (critical caribou habitat) in the 21 local population ranges totalled 6,103,534 ha, distributed among ~387,102 patches with 362,933 < 10 ha and 14 > 50,000 ha. The median percentage of local population ranges that was disturbed was 53.5%, with Charlevoix having the maximum (90.3%) and Basse Côte-Nord the least (34.9%). Woodland caribou local population ranges with disturbed suitable habitats >35% are considered unable to support self-sustaining populations. We found that for the 21 caribou local population ranges examined, 3 were at very high risk (>75% area disturbed), 16 at high risk (>45 ≤ 75% area disturbed), and 2 at low risk (≤35% area disturbed). Major changes are needed in boreal forest management in Ontario and Quebec for it to be ecologically sustainable, including a greater emphasis on protection and restoration for older forests, and to lower the risks for caribou populations. [ABSTRACT FROM AUTHOR]

Distinct aggregated proteins are correlated with numerous neurodegenerative diseases and the development of ligands that selectively detect these pathological hallmarks is vital. Recently, the synthesis of thiophene‐based optical ligands, denoted bi‐thiophene‐vinyl‐benzothiazoles (bTVBTs), that could be utilized for selective assignment of tau pathology in brain tissue with Alzheimer's disease (AD) pathology, was reported. Herein, we investigate the ability of these ligands to selectively distinguish tau deposits from aggregated amyloid‐β (Aβ), the second AD associated pathological hallmark, when replacing the terminal thiophene moiety with other heterocyclic motifs. The selectivity for tau pathology was reduced when introducing specific heterocyclic motifs, verifying that specific molecular interactions between the ligands and the aggregates are necessary for selective detection of tau deposits. In addition, ligands having certain heterocyclic moieties attached to the central thiophene‐vinylene building block displayed selectivity to aggregated Aβ pathology. Our findings provide chemical insights for the development of ligands that can distinguish between aggregated proteinaceous species consisting of different proteins and might also aid in creating novel agents for clinical imaging of tau pathology in AD. [ABSTRACT FROM AUTHOR]

Expressions for analytical molecular gradients of core-excited states have been derived and implemented for the hierarchy of algebraic diagrammatic construction (ADC) methods up to extended second-order within the core–valence separation (CVS) approximation. We illustrate the use of CVS-ADC gradients by determining relaxed core-excited state potential energy surfaces and optimized geometries for water, formic acid, and benzene. For water, our results show that in the dissociative lowest core-excited state, a linear configuration is preferred. For formic acid, we find that the O K-edge lowest core-excited state is non-planar, a fact that is not captured by the equivalent core approximation where the core-excited atom with its hole is replaced by the "Z + 1" neighboring atom in the periodic table. For benzene, the core-excited state gradients are presented along the Jahn–Teller distorted geometry of the 1s → π* excited state. Our development may pave a new path to studying the dynamics of molecules in their core-excited states. [ABSTRACT FROM AUTHOR]

A theoretical and experimental study of the gas phase and liquid acetic acid based on resonant inelastic x-ray scattering (RIXS) spectroscopy is presented. We combine and compare different levels of theory for an isolated molecule for a comprehensive analysis, including electronic and vibrational degrees of freedom. The excitation energy scan over the oxygen K-edge absorption reveals nuclear dynamic effects in the core-excited and final electronic states. The theoretical simulations for the monomer and two different forms of the dimer are compared against high-resolution experimental data for pure liquid acetic acid. We show that the theoretical model based on a dimer describes the hydrogen bond formation in the liquid phase well and that this bond formation sufficiently alters the RIXS spectra, allowing us to trace these effects directly from the experiment. Multimode vibrational dynamics is accounted for in our simulations by using a hybrid time-dependent stationary approach for the quantum nuclear wave packet simulations, showing the important role it plays in RIXS. [ABSTRACT FROM AUTHOR]

While the anomalous non-additive size-dependencies of static dipole polarizabilities and van der Waals C6 dispersion coefficients of carbon fullerenes are well established, the widespread reported scalings for the latter (ranging from N2.2 to N2.8) call for a comprehensive first-principles investigation. With a highly efficient implementation of the linear complex polarization propagator, we have performed Hartree–Fock and Kohn–Sham density functional theory calculations of the frequency-dependent polarizabilities for fullerenes consisting of up to 540 carbon atoms. Our results for the static polarizabilities and C6 coefficients show scalings of N1.2 and N2.2, respectively, thereby deviating significantly from the previously reported values obtained with the use of semi-classical/empirical methods. Arguably, our reported values are the most accurate to date as they represent the first ab initio or first-principles treatment of fullerenes up to a convincing system size. [ABSTRACT FROM AUTHOR]

Expressions for the calculation of rotatory strengths using the algebraic diagrammatic construction (ADC) scheme of the polarization propagator in both length and velocity gauges have been implemented. This enables the simulation of electronic circular dichroism (ECD) spectra at the ADC level up to third order of perturbation theory. The ADC(n) methods produce rotatory strengths of comparable accuracy to those obtained with coupled cluster methods of corresponding approximation levels, as evaluated for methyloxirane, methylthiirane, dimethyloxirane, dimethylthiirane, hydrogen peroxide, and dihydrogen disulfide. ECD spectra of (1R)-camphor, (1R)-norcamphor, and (1R)-fenchone computed at the third order ADC(3) level of theory are shown to agree very favorably with experimental gas phase spectra, demonstrating the usefulness of ADC for the calculation of chiro-optical properties of organic molecules. ADC(2) in combination with the polarizable continuum model is shown to successfully reproduce the ECD spectrum of the L-epinephrine enantiomer in water, further demonstrating the applicability of this approach. [ABSTRACT FROM AUTHOR]

Within the self-consistent field approximation, computationally tractable expressions for the isotropic second-order hyperpolarizability have been derived and implemented for the calculation of two-photon absorption cross sections. The novel tensor average formulation presented in this work allows for the evaluation of isotropic damped cubic response functions using only ∼3.3% (one-photon off-resonance regions) and ∼10% (one-photon resonance regions) of the number of auxiliary Fock matrices required when explicitly calculating all the needed individual tensor components. Numerical examples of the two-photon absorption cross section in the one-photon off-resonance and resonance regions are provided for alanine–tryptophan and 2,5-dibromo-1,4-bis(2-(4-diphenylaminophenyl)vinyl)-benzene. Furthermore, a benchmark set of 22 additional small- and medium-sized organic molecules is considered. In all these calculations, a quantitative assessment is made of the reduced and approximate forms of the cubic response function in the one-photon off-resonance regions and results demonstrate a relative error of less than ∼5% when using the reduced expression as compared to the full form of the isotropic cubic response function. [ABSTRACT FROM AUTHOR]

We present the derivation and implementation of complex, frequency-dependent polarizabilities for excited states using the algebraic– diagrammatic construction for the polarization propagator (ADC) and its intermediate state representation. Based on the complex polarizability, we evaluate C6 dispersion coefficients for excited states. The methodology is implemented up to third order in perturbation theory in the Python-driven adcc toolkit for the development and application of ADC methods. We exemplify the approach using illustrative model systems and compare it to results from other ab initio methods and from experiments. [ABSTRACT FROM AUTHOR]

We describe a concise synthetic strategy for the preparation of heterocyclic [9]helicenes and a simple preparative‐scale protocol for the optical resolution of the resulting M‐ and P‐enantiomers. The helicenes were characterized by single‐crystal X‐ray diffraction along with a range of spectroscopic and computational techniques. A fluorescence quantum yield of up to 65 % was observed, and the chiroptical properties of both M‐ and P‐helicenes revealed large dissymmetry factors. The circularly polarized luminescence brightness reaches up to 17 M−1 cm−1, as measured experimentally and verified computationally, which makes this the highest circularly polarized luminescence brightness among heterocyclic helicenes. We describe how chiroptical properties (both circular dichroism and circularly polarized luminescence) can be described and predicted using quantum chemical calculations. The synthetic approach also reveals by‐products that originate from internal oxidation reactions, presumably mediated by the close proximity of the π‐surfaces in the helicene structure. [ABSTRACT FROM AUTHOR]

Context: Climate-induced changes of alpine vegetation diversity, cover and composition have been recorded globally, but most insights have been gleaned from field studies over small spatiotemporal scales. Aims: We assess dynamics in climate and vegetation of Australia's highest and most biologically diverse alpine area that surrounds Mount Kosciuszko (~455 km2), as well as recovery following the 2003 wildfires. Methods: Climatic changes were analysed using gridded climate data for mean annual temperature (1910–2019) and seasonal precipitation (1900–2019), and changes in snow cover were assessed from snow course records (1954–2021). A vegetation cover time series (1990, 2000, 2010, 2020) was modelled with an optimised random forest classification using recursive feature selection, and the LandTrendr algorithm was used to detect areas burnt during wildfires. Key results: Over time, temperatures and summer precipitation increased, whereas snow cover and winter precipitation decreased. Subsequently, vegetation dynamics were dominated by the densification of subalpine woodlands at lower elevations, replacing dry and wet heathlands. There was treeline stasis but upslope advancement of dry and wet shrublines but grassland vegetation types were relatively stable. However, in burnt areas there was suppressed upslope advancement of shrublines, treeline recession and relatively less expansion of subalpine woodlands. Conclusions: Alpine vegetation may be impacted by climate change incrementally through relatively gradual changes in climatic conditions, and transformatively through landscape-level disturbance from wildfires. Implications: Higher temperatures and altered precipitation regimes increase the frequency and severity of wildfires, which may be amplified by increasing fuel loads and dryness from the proliferation and advance of woody vegetation in alpine areas. Climate change is driving changes in alpine vegetation as well as leading to intensifying wildfire regimes. Here, we assess changes in climate and vegetation for Australia's highest and most biologically diverse alpine area using remote sensing data. As the climate has warmed, precipitation regimes have changed and snow cover has declined, the cover of woody vegetation has increased through densification at the treeline and upslope migration of shrublines, leading to increased landscape flammability. [ABSTRACT FROM AUTHOR]

The More‐Electric Engine (MEE), with its electrified engine auxiliary systems and increased multi‐shaft power offtake, is likely to become an increasingly central aspect of future More‐Electric Aircraft. Consequently, lightweight but resilient electrical power architectures are needed for these future MEE applications. However, whilst a range of MEE architectures exist in the research literature, no effective baseline architecture or standardised feature identification has been proposed to specifically address their unique design requirements. Accordingly, any underpinning technology‐focused research for critical MEE subsystems may ultimately have a reduced effectiveness without this credible baseline. Based on comprehensive design analyses, preliminary design requirements and anticipated operational modes, this article proposes key design rules for the formation of the first generic baseline MEE electrical power system architecture concept. Guidance is provided on features such as the number of power generation systems, the number and topologies of distribution channels, type of power conversion, essential load redundancy, and the location of emergency power supply. This article also provides full transparency of the design process so that key decision points can be revisited to capture application‐ specific requirements and updates to certification requirements. [ABSTRACT FROM AUTHOR]

Deepening droughts and unprecedented wildfires are at the leading edge of climate change. Such events pose an emerging threat to species maladapted to these perturbations, with the potential for steeper declines than may be inferred from the gradual erosion of their climatic niche. This study focused on two species of amphibians—Philoria kundagungan and Philoria richmondensis (Limnodynastidae)—from the Gondwanan rainforests of eastern Australia that were extensively affected by the "Black Summer" megafires of 2019/2020 and the severe drought associated with them. We sought to assess the impact of these perturbations by quantifying the extent of habitat affected by fire, assessing patterns of occurrence and abundance of calling males post‐fire, and comparing post‐fire occurrence and abundance with that observed pre‐fire. Some 30% of potentially suitable habitat for P. kundagungan was fire affected, and 12% for P. richmondensis. Field surveys revealed persistence in some burnt rainforest; however, both species were detected at a higher proportion of unburnt sites. There was a clear negative effect of fire on the probability of site occupancy, abundance and the probability of persistence for P. kundagungan. For P. richmondensis, effects of fire were less evident due to the limited penetration of fire into core habitat; however, occupancy rates and abundance of calling males were depressed during the severe drought that prevailed just prior to the fires, with the reappearance of calling males linked to the degree of rehydration of breeding habitat post‐fire. Our results highlight the possibility that severe negative impacts of climate change for montane rainforest endemics may be felt much sooner than commonly anticipated under a scenario of gradual (decadal‐scale) changes in mean climatic conditions. Instead, the increased rate of severe stochastic events places these narrow range species at a heightened risk of extinction in the near‐term. [ABSTRACT FROM AUTHOR]

We report on a combined theoretical and experimental study of core-excitation spectra of gas and liquid phase methanol as obtained with the use of X-ray absorption spectroscopy (XAS) and resonant inelastic X-ray scattering (RIXS). The electronic transitions are studied with computational methods that include strict and extended second-order algebraic diagrammatic construction [ADC(2) and ADC(2)-x], restricted active space second-order perturbation theory, and time-dependent density functional theory—providing a complete assignment of the near oxygen K-edge XAS. We show that multimode nuclear dynamics is of crucial importance for explaining the available experimental XAS and RIXS spectra. The multimode nuclear motion was considered in a recently developed "mixed representation" where dissociative states and highly excited vibrational modes are accurately treated with a time-dependent wave packet technique, while the remaining active vibrational modes are described using Franck–Condon amplitudes. Particular attention is paid to the polarization dependence of RIXS and the effects of the isotopic substitution on the RIXS profile in the case of dissociative core-excited states. Our approach predicts the splitting of the 2a″ RIXS peak to be due to an interplay between molecular and pseudo-atomic features arising in the course of transitions between dissociative core- and valence-excited states. The dynamical nature of the splitting of the 2a″ peak in RIXS of liquid methanol near pre-edge core excitation is shown. The theoretical results are in good agreement with our liquid phase measurements and gas phase experimental data available from the literature. [ABSTRACT FROM AUTHOR]

The modification of the algebraic-diagrammatic construction (ADC) scheme for the polarization propagator using ground-state coupled-cluster (CC) instead of Møller–Plesset (MP) amplitudes, referred to as CC-ADC, is extended to the calculation of molecular properties, in particular, dipole polarizabilities. Furthermore, in addition to CC with double excitations (CCD), CC with single and double excitations (CCSD) amplitudes can be used, also in the second-order transition moments of the ADC(3/2) method. In the second-order CC-ADC(2) variants, the MP correlation coefficients occurring in ADC are replaced by either CCD or CCSD amplitudes, while in the F/CC-ADC(2) and F/CC-ADC(3/2) variants, they are replaced only in the second-order modified transition moments. These newly implemented variants are used to calculate the static dipole polarizability of several small- to medium-sized molecules, and the results are compared to the ones obtained by full configuration interaction or experiment. It is shown that the results are consistently improved by the use of CC amplitudes, in particular, for aromatic systems such as benzene or pyridine, which have proven to be difficult cases for standard ADC approaches. In this case, the second-order CC-ADC(2) and F/CC-ADC(2) variants yield significantly better results than the standard third-order ADC(3/2) method, at a computational cost amounting to only about 1% of the latter. [ABSTRACT FROM AUTHOR]

Context: Dietary consumption of phosphate is increasing, and elevated serum phosphate is associated with increased cardiovascular disease (CVD) risk. Sex differences in phosphate homeostasis and response to changes in dietary phosphate intake, which are not captured by clinically measured analytes, may contribute to differences in CVD presentation and bone disease. Objective: To assess sex differences in acute phosphate homeostasis in response to a single oral phosphate challenge. Design: Cross-sectional. Setting: General community. Participants: 78 participants (40-76 years) with measured glomerular filtration rate >60 mL/min/1.73 m² and no clinically diagnosed CVD and 14 young healthy adults. Main Outcome Measures: To elucidate subtle alterations in phosphate homeostasis, we employ an acute challenge whereby the hormonal response, circulating mineral levels, and urinary excretion are assessed following an oral challenge of phosphate. Results: Although both males and females had similar changes in circulating phosphate, calcium, and parathyroid hormone in response to the challenge, females excreted ~1.9x more phosphate and ~2.7x more calcium than males, despite not consuming calcium. These sex differences were recapitulated in healthy young adults. This excretion response did not correlate to age, serum phosphate, or estradiol levels. The females with greater excretion of phosphate had higher levels of bone resorption markers compared to formation markers. Conclusions: Taken together, these data identify sex differences in acute phosphate homeostasis, specifically that females may mobilize and excrete endogenous sources of calcium and phosphate in response to oral phosphate compared to males. While high levels of dietary phosphate negatively impact bone, our results suggest that females may incur more risk from these diets. [ABSTRACT FROM AUTHOR]

Background Vitamin K activates matrix Gla protein (MGP), a key inhibitor of vascular calcification. There is a high prevalence of sub-clinical vitamin K deficiency in patients with end-stage kidney disease. Methods A parallel randomized placebo-controlled pilot trial was designed to determine whether 10 mg of phylloquinone thrice weekly versus placebo modifies coronary artery calcification progression over 12 months in patients requiring hemodialysis with a coronary artery calcium score (CAC) ≥30 Agatston Units (ClinicalTrials.gov identifier NCT01528800). The primary outcome was feasibility (recruitment rate, compliance with study medication, study completion and adherence overall to study protocol). CAC score was used to assess calcification at baseline and 12 months. Secondary objectives were to explore the impact of phylloquinone on vitamin K-related biomarkers (phylloquinone, dephospho-uncarboxylated MGP and the Gla-osteocalcin to Glu-osteocalcin ratio) and events of clinical interest. Results A total of 86 patients with a CAC score ≥30 Agatston Units were randomized to either 10 mg of phylloquinone or a matching placebo three times per week. In all, 69 participants (80%) completed the trial. Recruitment rate (4.4 participants/month) and medication compliance (96%) met pre-defined feasibility criteria of ≥4.17 and ≥90%, respectively. Patients randomized to phylloquinone for 12 months had significantly reduced levels of dephospho-uncarboxylated MGP (86% reduction) and increased levels of phylloquinone and Gla-osteocalcin to Glu-osteocalcin ratio compared with placebo. There was no difference in the absolute or relative progression of coronary artery calcification between groups. Conclusion We demonstrated that phylloquinone treatment improves vitamin K status and that a fully powered randomized trial may be feasible. [ABSTRACT FROM AUTHOR]

A methodology is developed to compute photoionization cross sections beyond the electric dipole approximation from response theory, using Gaussian type orbitals and plane waves for the initial and final states, respectively. The methodology is applied to compute photoionization cross sections of atoms and ions from the first four rows of the periodic table. Analyzing the error due to the plane wave description of the photoelectron, we find kinetic energy and concomitant photon energy thresholds above which the plane wave approximation becomes applicable. The correction introduced by going beyond the electric dipole approximation increases with photon energy and depends on the spatial extension of the initial state. In general, the corrections are below 10% for most elements, at a photon energy reaching up to 12 keV. [ABSTRACT FROM AUTHOR]

We calibrate basis sets and performance of two theoretical approaches to compute X-ray absorption spectra (XAS) of condensed water by comparison to experiments on hexagonal ice Ih. We apply both the transition-potential half-core-hole approach and the complex polarization propagator using four different models of the crystal with increasing oxygen and proton disorder but find poor agreement with experiments. We note that there are large variations in experimental spectra depending on detection mode and how the ice samples were prepared, which leads us to critically investigate what structures were actually prepared and measured in each case. This is done by using a Monte Carlo-based fitting technique which fits the spectra based on a library of precomputed spectra and assigns weights to contributions from different model structures. These are then used to generate O–O and O–H radial distribution functions and tetrahedrality parameters associated with each of the measured spectra. We find that all spectra are associated with sharp peaks at the oxygen positions in the perfect lattice, but with significant disorder around these positions. We suggest that presently available XAS of hexagonal ice are not fully representative of the perfect crystalline lattice, but contain varying amounts of defects and possible contributions from low-density amorphous ice. [ABSTRACT FROM AUTHOR]

Biomimetic chiral optoelectronic materials can be utilized in electronic devices, biosensors and artificial enzymes. Herein, this work reports the chiro‐optical properties and architectural arrangement of optoelectronic materials generated from self‐assembly of initially nonchiral oligothiophene−porphyrin derivatives and random coil synthetic peptides. The photo‐physical‐ and structural properties of the materials were assessed by absorption‐, fluorescence‐ and circular dichroism spectroscopy, as well as dynamic light scattering, scanning electron microscopy and theoretical calculations. The materials display a three‐dimensional ordered helical structure and optical activity that are observed due to an induced chirality of the optoelectronic element upon interaction with the peptide. Both these properties are influenced by the chemical composition of the oligothiophene−porphyrin derivative, as well as the peptide sequence. We foresee that our findings will aid in developing self‐assembled optoelectronic materials with dynamic architectonical accuracies, as well as offer the possibility to generate the next generation of materials for a variety of bioelectronic applications. [ABSTRACT FROM AUTHOR]

Background: Inadequate pain control after median sternotomy leads to reduced mobilization, increased respiratory complications, and longer hospital stays. Typically, postoperative pain is controlled by opioid analgesics that may have several adverse effects. Parasternal intercostal block (PSB) has emerged as part of a multimodal strategy to control pain after median sternotomy. However, the effectiveness of this intervention on postoperative pain control and analgesic use has not been fully established. Methods and Results: We conducted a meta‐analysis to assess the effect of PSB on postoperative pain and analgesic use in adult cardiac surgery patients undergoing median sternotomy. PubMed, Embase, Google Scholar, and the Cochrane database were searched with the following search strategy: ([postoperative pain] or [pain relief] OR [analgesics] or [analgesia] or [nerve block] or [regional block] or [local block] or [regional anesthesia] or [local anesthetic] or [parasternal block] and [sternotomy]) and (humans [filter]). Inclusion criteria were: patients who underwent cardiac surgery via median sternotomy, age >18 and parasternal block (continuous and single dose). Exclusion criteria were: noncardiac surgery, nonparasternal nerve blocks, and the use of NSAIDS in parasternal block. Quality assessment was performed by three independent reviewers via the Cochrane risk of bias assessment tool. Of 1165 total citations, 18 were found to be relevant. Of these 18 citations, 7 citations (N = 2223 patients) reported postoperative pain scores in an extractable format and 11 citations (N = 2155 patients) reported postoperative opioid use in an extractable format. For postoperative opioid use, morphine equivalent doses were calculated for all studies and postoperative pain scores were standardized to a 10‐point visual analog scale for comparison between studies; both these were reported as total opioid use or cumulative score ranging from 24 to 72 h postoperative. All data analyses were run using a random effects model, using a restricted maximum likelihood estimator, to obtain summary standardized mean differences with 95% confidence interval (CI's). For studies which only reported median and interquatile range (IQR), the median was standard deviation was estimated by IQR/1.35. Following median sternotomy both postoperative pain (SMD [95% CI] −0.49 [−0.92 to −0.06]) and postoperative morphine equivalent use (SMD [95% CI] −1.68 [−3.11 to −0.25]) were significantly less in the PSB group. Conclusion: Our meta‐analysis suggests that parasternal nerve block significantly reduces postoperative pain and opioid use. [ABSTRACT FROM AUTHOR]

We demonstrate that contemporary computational resources allow for accurate theoretical studies of systems matching recent advances in experimental helicene chemistry. Concerned with first-principles calculations of carbohelicenes, our work surpasses CH[12] as the largest system investigated to date and unravels trends in the electronic structure of the low-lying states of the homologous series. Utilizing a highly efficient implementation of linear response algorithms, we present electronic circular dichroism (CD) spectra of carbohelicenes ranging from CH[5] to CH[30] at the level of Kohn–Sham density-functional theory. Our results for a systematic increase in system size show the emergence of new CD bands that subsequently rise to intensities dominating the spectrum. The spectral band progressions exhibit a periodicity directly linked to the number of overlapping layers of conjugation. While our findings rectify the current understanding of the electronic structure of carbohelicenes, they also serve as a general call for caution regarding the extrapolation of trends from small system ranges. [ABSTRACT FROM AUTHOR]

The second-order nonlinear (or cubic) response function is derived from the Ehrenfest theorem with inclusion made of the finite lifetimes of the excited states, representing the extension of the derivation of the quadratic response function in the same framework [P. Norman et al., J. Chem. Phys. 123, 194103 (2005)]. The resulting damped response functions are physically sound and converging also in near-resonance and resonance regions of the spectrum. Being an accurate approximation for small complex frequencies (defined as the sum of an optical frequency and an imaginary damping parameter), the polynomial expansion of the complex cubic response function in terms of the said frequencies is presented and used to validate the program implementation. In terms of approximate state theory, the computationally tractable expressions of the damped cubic response function are derived and implemented at the levels of Hartree-Fock and Kohn-Sham density functional theory. Numerical examples are provided in terms of studies of the intensity-dependent refractive index of para-nitroaniline and the two-photon absorption cross section of neon. For the latter property, a numerical comparison is made against calculations of the square of two-photon matrix elements that are identified from a residue analysis of the resonance-divergent quadratic response function. [ABSTRACT FROM AUTHOR]

We present a derivation of linear response theory within polarizable embedding starting from a rigorous quantum-mechanical treatment of a composite system. To this aim, two different subsystem decompositions (symmetric and nonsymmetric) of the linear response function are introduced and the pole structures as well as residues of the individual terms are discussed. In addition to providing a thorough justification for the descriptions used in polarizable embedding models, this theoretical analysis clarifies which form of the response function to use and highlights complications in separating out subsystem contributions to molecular properties. The basic features of the presented expressions and various approximate forms are illustrated by their application to a composite model system. [ABSTRACT FROM AUTHOR]

We present a derivation of linear response theory within polarizable embedding starting from a rigorous quantum-mechanical treatment of a composite system. To this aim, two different subsystem decompositions (symmetric and nonsymmetric) of the linear response function are introduced and the pole structures as well as residues of the individual terms are discussed. In addition to providing a thorough justification for the descriptions used in polarizable embedding models, this theoretical analysis clarifies which form of the response function to use and highlights complications in separating out subsystem contributions to molecular properties. The basic features of the presented expressions and various approximate forms are illustrated by their application to a composite model system. [ABSTRACT FROM AUTHOR]

Chronic kidney disease (CKD) results in calcitriol deficiency and altered vitamin D metabolism. The objective of this study was to assess the 24-hydroxylation-mediated metabolism of 25(OH)D3 and 1,25(OH)2D3 in a cross-sectional analysis of participants with a range of kidney function assessed by precise measured GFR (mGFR) (N = 143) and in rats with the induction and progression of experimental kidney disease. Vitamin D metabolites were assessed with LC–MS/MS. Circulating measures of 24-hydroxylation of 25(OH)D3 (24,25(OH)2D3:25(OH)D3) precisely decreased according to mGFR in humans and progressively in rats with developing CKD. In contrast, the 1,24,25(OH)3D3: 1,25(OH)2D3 vitamin D metabolite ratio increased in humans as the mGFR decreased and in rats with the induction and progression of CKD. Human participants taking cholecalciferol had higher circulating 1,24,25(OH)3D3, despite no increase of 1,25(OH)2D3. This first report of circulating 1,24,25(OH)3D3 in the setting of CKD provides novel insight into the uniquely altered vitamin D metabolism in this setting. A better understanding of the uniquely dysfunctional catabolic vitamin D profile in CKD may guide more effective treatment strategies. The potential that 24-hydroxylated products have biological activity of is an important area of future research. [ABSTRACT FROM AUTHOR]

Background: Cultures of safety in farm work settings are under the authority of a responsible owner‐operator, who establishes rules, attitudes, and behaviors for farm work practices. This novel analysis provides new evidence to show that risks that can lead to injury and are commonly practiced on Canadian farms are indeed transferred between generations. Methods: Baseline data were provided by representatives from eligible and consenting farms (n = 589) in the province of Saskatchewan, Canada, during the first quarter of 2013. Mailed questionnaires were sent to participating farms and completed by a single respondent. Questionnaires included scaled assessments of hazards and safety practices by farm operators, and young workers on each farm. Descriptive and multiple regression analyses were used to examine relationships between farm owner‐operator risks and safety practices and those reported for the young workers. Findings: Graphical descriptive analyses showed that as farm owner‐operator risks increased, so did those reported for children and young workers. Similarly, as farm owner‐operator safe work practices increased, young worker hazards decreased, albeit more modestly. The young worker hazard scale increased by 0.20 (95% CI: 0.10‐0.30) points, and decreased by 0.08 (95% CI: –0.016 to –0.000) points for each one‐point increase in the owner‐operator hazard and safe work practices scales, respectively. Conclusions: Occupational health and safety risks and protections experienced on farms appear to be transferred between generations. This suggests the need to target farm owner‐operators, the responsible authority on the farm, as a focus of primary prevention strategies aimed at injury risks to children and young workers. [ABSTRACT FROM AUTHOR]

Background: L-carnitine (L-C), a ubiquitous nutritional supplement, has been investigated as a potential therapy for cardiovascular disease, but its effects on human atherosclerosis are unknown. Clinical studies suggest improvement of some cardiovascular risk factors, whereas others show increased plasma levels of pro-atherogenic trimethylamine N-oxide. The primary aim was to determine whether L-C therapy led to progression or regression of carotid total plaque volume (TPV) in participants with metabolic syndrome (MetS). Methods: This was a phase 2, prospective, double blinded, randomized, placebo-controlled, two-center trial. MetS was defined as ≥ 3/5 cardiac risk factors: elevated waist circumference; elevated triglycerides; reduced HDL-cholesterol; elevated blood pressure; elevated glucose or HbA1c; or on treatment. Participants with a baseline TPV ≥ 50 mm3 were randomized to placebo or 2 g L-C daily for 6 months. Results: The primary outcome was the percent change in TPV over 6 months. In 157 participants (L-C N = 76, placebo N = 81), no difference in TPV change between arms was found. The L-C group had a greater increase in carotid atherosclerotic stenosis of 9.3% (p = 0.02) than the placebo group. There was a greater increase in total cholesterol and LDL-C levels in the L-C arm. Conclusions: Though total carotid plaque volume did not change in MetS participants taking L-C over 6-months, there was a concerning progression of carotid plaque stenosis. The potential harm of L-C in MetS and its association with pro-atherogenic metabolites raises concerns for its further use as a potential therapy and its widespread availability as a nutritional supplement. Trial registration: ClinicalTrials.gov, NCT02117661, Registered April 21, 2014, https://clinicaltrials.gov/ct2/show/NCT02117661. [ABSTRACT FROM AUTHOR]

The van derWaals C6 coefficients of fullerenes are shown to exhibit an anomalous dependence on the number of carbon atoms N such that C6 ∝ N2.2 as predicted using state-of-the-art quantum mechanical calculations based on fullerenes with small sizes, and N2.75 as predicted using a classical-metallic spherical-shell approximation of the fullerenes. We use an atomistic electrodynamics model where each carbon atom is described by a polarizable object to extend the quantum mechanical calculations to larger fullerenes. The parameters of this model are optimized to describe accurately the static and complex polarizabilities of the fullerenes by fitting against accurate ab initio calculations. This model shows that C6 ∝ N2.8, which is supportive of the classical-metallic spherical-shell approximation. Additionally, we show that the anomalous dependence of the polarizability on N is attributed to the electric charge term, while the dipole-dipole term scales almost linearly with the number of carbon atoms. [ABSTRACT FROM AUTHOR]

The van derWaals C6 coefficients of fullerenes are shown to exhibit an anomalous dependence on the number of carbon atoms N such that C6 ∝ N2.2 as predicted using state-of-the-art quantum mechanical calculations based on fullerenes with small sizes, and N2.75 as predicted using a classical-metallic spherical-shell approximation of the fullerenes. We use an atomistic electrodynamics model where each carbon atom is described by a polarizable object to extend the quantum mechanical calculations to larger fullerenes. The parameters of this model are optimized to describe accurately the static and complex polarizabilities of the fullerenes by fitting against accurate ab initio calculations. This model shows that C6 ∝ N2.8, which is supportive of the classical-metallic spherical-shell approximation. Additionally, we show that the anomalous dependence of the polarizability on N is attributed to the electric charge term, while the dipole-dipole term scales almost linearly with the number of carbon atoms. [ABSTRACT FROM AUTHOR]

The desorption of a carbon monoxide molecule from a Ru(0001) surface was studied by means of X-ray Absorption Spectra (XAS) computed with Transition Potential (TP-DFT) and Time Dependent (TD-DFT) DFT methods. By unraveling the evolution of the CO electronic structure upon desorption, we observed that at 2.3 Å from the surface, the CO molecule has already predominantly gas-phase character. While C 1s XAS is quite insensitive to changes in the C–O bond length, the O 1s excitation is very sensitive with the π* coming down in energy upon CO bond stretching, which competes with the increase in orbital energy due to the repulsive interaction with the metallic surface. We show in a systematic way that the TP-DFT method can describe the XAS rather well at the endpoints (chemisorbed and gas phase) but is affected by artificial charge transfer and/or incorrect spin treatment in the transition region in cases like CO, where there are low-lying π* orbitals and large exchange interactions between the core 1s and valence-acceptor π* orbitals. As an alternative, we demonstrate by comparing with experimental data that a linear response approach using TD-DFT employing common exchange-correlation functionals and finite-size clusters can yield a good description of the spectral evolution of the 1s → π* transition with correct spin and gas-to-chemisorbed chemical shifts in good agreement with experiment. [ABSTRACT FROM AUTHOR]

The synthesis, structures, and properties of [4]cyclonaphthodithiophene diimides ([4]C‐NDTIs) are described. NDTIs as important n‐type building blocks were catenated in the α‐positions of thiophene rings via an unusual electrochemical‐oxidation‐promoted macrocyclization route. The thiophene–thiophene junction in [4]C‐NDTIs results in an ideal pillar shape. This interesting topology, along with appealing electronic and optical properties inherited from the NDTI units, endows the [4]C‐NDTIs with both near‐infrared (NIR) light absorptions, strong excitonic coupling, and tight encapsulation of C60. Stable orientations of the NDTI units in the nanopillars lead to stable inherent chirality, which enables detailed circular dichroism studies on the impact of isomeric structures on π‐conjugation. Remarkably, the [4]C‐NDTIs maintain the strong π–π stacking abilities of NDTI units and thus adopt two‐dimensional (2D) lattice arrays at the molecular level. These nanopillar molecules have great potential to mimic natural photosynthetic systems for the development of multifunctional organic materials. [ABSTRACT FROM AUTHOR]

The synthesis, structures, and properties of [4]cyclonaphthodithiophene diimides ([4]C‐NDTIs) are described. NDTIs as important n‐type building blocks were catenated in the α‐positions of thiophene rings via an unusual electrochemical‐oxidation‐promoted macrocyclization route. The thiophene–thiophene junction in [4]C‐NDTIs results in an ideal pillar shape. This interesting topology, along with appealing electronic and optical properties inherited from the NDTI units, endows the [4]C‐NDTIs with both near‐infrared (NIR) light absorptions, strong excitonic coupling, and tight encapsulation of C60. Stable orientations of the NDTI units in the nanopillars lead to stable inherent chirality, which enables detailed circular dichroism studies on the impact of isomeric structures on π‐conjugation. Remarkably, the [4]C‐NDTIs maintain the strong π–π stacking abilities of NDTI units and thus adopt two‐dimensional (2D) lattice arrays at the molecular level. These nanopillar molecules have great potential to mimic natural photosynthetic systems for the development of multifunctional organic materials. [ABSTRACT FROM AUTHOR]

The Gator program has been developed for computational spectroscopy and calculations of molecular properties using real and complex propagators at the correlated level of wave function theory. Currently, the focus lies on methods based on the algebraic diagrammatic construction (ADC) scheme up to the third order of perturbation theory. An auxiliary Fock matrix‐driven implementation of the second‐order ADC method for excitation energies has been realized with an underlying hybrid MPI/OpenMP parallelization scheme suitable for execution in high‐performance computing cluster environments. With a modular and object‐oriented program structure written in a Python/C++ layered fashion, Gator additionally enables time‐efficient prototyping of novel scientific approaches, as well as interactive notebook‐driven training of students in quantum chemistry. This article is categorized under:Computer and Information Science > Computer Algorithms and ProgrammingElectronic Structure Theory > Ab Initio Electronic Structure MethodsSoftware > Quantum Chemistry [ABSTRACT FROM AUTHOR]

We present a formulation of molecular response theory for the description of a quantum mechanical molecular system in the presence of a weak, monochromatic, linearly polarized electromagnetic field without introducing truncated multipolar expansions. The presentation focuses on a description of linear absorption by adopting the energy-loss approach in combination with the complex polarization propagator formulation of response theory. Going beyond the electric-dipole approximation is essential whenever studying electric-dipole-forbidden transitions, and in general, non-dipolar effects become increasingly important when addressing spectroscopies involving higher-energy photons. These two aspects are examined by our study of the near K-edge X-ray absorption fine structure of the alkaline earth metals (Mg, Ca, Sr, Ba, and Ra) as well as the trans-polyenes. In following the series of alkaline earth metals, the sizes of non-dipolar effects are probed with respect to increasing photon energies and a detailed assessment of results is made in terms of studying the pertinent transition electron densities and in particular their spatial extension in comparison with the photon wavelength. Along the series of trans-polyenes, the sizes of non-dipolar effects are probed for X-ray spectroscopies on organic molecules with respect to the spatial extension of the chromophore. [ABSTRACT FROM AUTHOR]

Recent years have witnessed a growing interest in magneto-optic spectroscopy techniques that use nuclear magnetization as the source of the magnetic field. Here we present a formulation of magnetic circular dichroism (CD) due to magnetically polarized nuclei, nuclear spin-induced CD (NSCD), in molecules. The NSCD ellipticity and nuclear spin-induced optical rotation (NSOR) angle correspond to the real and imaginary parts, respectively, of (complex) quadratic response functions involving the dynamic second-order interaction of the electron system with the linearly polarized light beam, as well as the static magnetic hyperfine interaction. Using the complex polarization propagator framework, NSCD and NSOR signals are obtained at frequencies in the vicinity of optical excitations. Hartree-Fock and density-functional theory calculations on relatively small model systems, ethene, benzene, and 1,4-benzoquinone, demonstrate the feasibility of the method for obtaining relatively strong nuclear spin-induced ellipticity and optical rotation signals. Comparison of the proton and carbon-13 signals of ethanol reveals that these resonant phenomena facilitate chemical resolution between non-equivalent nuclei in magneto-optic spectra. [ABSTRACT FROM AUTHOR]

Since dc distribution minimizes the number of power conversion stages, it lowers the overall cost, power losses, and weight of a power system. Critical systems use IT grounding because it is tolerant to the first-fault. Hence, this is an attractive option for hybrid electric aircraft (HEA), which combines gas engines with electric motors driven by power electronic converters. This letter proposes an accurate implementation for the procedure of first-fault detection with IT grounding. The ac component injection along with the sliding discrete Fourier transform (SDFT) is used to estimate the fault impedance. The procedure is very accurate due to the heavy filtering of the implicit moving average filter. Further computation savings are obtained by using the double look-up tables, and the Goertzel algorithm for the SDFT. Results are validated by simulations and experiments. [ABSTRACT FROM AUTHOR]

Quenching of vibrational excitations in resonant inelastic X-ray scattering (RIXS) spectra of liquid acetic acid is observed. At the oxygen core resonance associated with localized excitations at the O–H bond, the spectra lack the typical progression of vibrational excitations observed in RIXS spectra of comparable systems. We interpret this phenomenon as due to strong rehybridization of the unoccupied molecular orbitals as a result of hydrogen bonding, which however cannot be observed in x-ray absorption but only by means of RIXS. This allows us to address the molecular structure of the liquid, and to determine a lower limit for the average molecular chain length. [ABSTRACT FROM AUTHOR]