Spectral Evidence for Emergent Order in Ba_{1-x}Na_{x}Fe_{2}As_{2}.

We report an angle-resolved photoemission spectroscopy study of the iron-based superconductor family, Ba_{1-x}Na_{x}Fe_{2}As_{2}. This system harbors the recently discovered double-Q magnetic order appearing in a reentrant C_{4} phase deep within the underdoped regime of the phase diagram that is otherwise dominated by the coupled nematic phase and collinear antiferromagnetic order. From a detailed temperature-dependence study, we identify the electronic response to the nematic phase in an orbital-dependent band shift that strictly follows the rotational symmetry of the lattice and disappears when the system restores C_{4} symmetry in the low temperature phase. In addition, we report the observation of a distinct electronic reconstruction that cannot be explained by the known electronic orders in the system.

Structural and functional analysis of the finished genome of the recently isolated toxic Anabaena sp. WA102.

BACKGROUND: Very few closed genomes of the cyanobacteria that commonly produce toxic blooms in lakes and reservoirs are available, limiting our understanding of the properties of these organisms. A new anatoxin-a-producing member of the Nostocaceae, Anabaena sp. WA102, was isolated from a freshwater lake in Washington State, USA, in 2013 and maintained in non-axenic culture. RESULTS: The Anabaena sp. WA102 5.7 Mbp genome assembly has been closed with long-read, single-molecule sequencing and separately a draft genome assembly has been produced with short-read sequencing technology. The closed and draft genome assemblies are compared, showing a correlation between long repeats in the genome and the many gaps in the short-read assembly. Anabaena sp. WA102 encodes anatoxin-a biosynthetic genes, as does its close relative Anabaena sp. AL93 (also introduced in this study). These strains are distinguished by differences in the genes for light-harvesting phycobilins, with Anabaena sp. AL93 possessing a phycoerythrocyanin operon. Biologically relevant structural variants in the Anabaena sp. WA102 genome were detected only by long-read sequencing: a tandem triplication of the anaBCD promoter region in the anatoxin-a synthase gene cluster (not triplicated in Anabaena sp. AL93) and a 5-kbp deletion variant present in two-thirds of the population. The genome has a large number of mobile elements (160). Strikingly, there was no synteny with the genome of its nearest fully assembled relative, Anabaena sp. 90. CONCLUSION: Structural and functional genome analyses indicate that Anabaena sp. WA102 has a flexible genome. Genome closure, which can be readily achieved with long-read sequencing, reveals large scale (e.g., gene order) and local structural features that should be considered in understanding genome evolution and function.

Magnetostriction and Magnetostructural Domains in Antiferromagnetic YBa2Cu3O6.

We use high-resolution neutron Larmor diffraction and capacitative dilatometry to investigate spontaneous and forced magnetostriction in undoped, antiferromagnetic YBa_{2}Cu_{3}O_{6.0}, the parent compound of a prominent family of high-temperature superconductors. Upon cooling below the Néel temperature T_{N}=420 K, Larmor diffraction reveals the formation of magnetostructural domains of characteristic size ∼240 nm. In the antiferromagnetic state, dilatometry reveals a minute (4×10^{-6}) orthorhombic distortion of the crystal lattice in external magnetic fields. We attribute these observations to exchange striction and spin-orbit coupling induced magnetostriction, respectively, and show that they have an important influence on the thermal and charge transport properties of undoped and lightly doped cuprates.

Electronic Spectra of Protonated Fluoranthene in a Neon Matrix and Gas Phase at 10 K.

Four electronic systems with origin bands at 759.5, 559.3, 476.3, and 385.5 nm are detected in a 6 K neon matrix following deposition of mass-selected protonated fluoranthene C16H11(+) produced from a reaction of neutral vapor and ethanol in a hot-cathode ion source. Two cationic isomers are identified as the carriers of these band systems. The 559.3, 476.3, and 385.5 nm absorptions are assigned to 4,3,2 (1)A' ← X (1)A' transitions of isomer E(+) (γ-) and the 2 (1)A' ← X (1)A' system at 759.5 nm is of isomer C(+) (α-) of protonated fluoranthene on the basis of theoretical predictions. The electronic spectrum of E(+) was also recorded in the gas phase using a resonant 1 + 1 two-photon excitation-dissociation technique in an ion trap at vibrational and rotational temperatures of 10 K. The 3,2 (1)A' ← X (1)A' transitions have origin band maxima at 558.28 ± 0.01 and 474.92 ± 0.01 nm. Both the 2 (1)A' and 3 (1)A' excited states have a distinct vibrational pattern with lifetimes on the order of 1 ps.

Infrared Study of the Spin Reorientation Transition and Its Reversal in the Superconducting State in Underdoped Ba(1-x)K(x)Fe(2)As(2).

With infrared spectroscopy we investigated the spin-reorientation transition from an orthorhombic antiferromagnetic (o-AF) to a tetragonal AF (t-AF) phase and the reentrance of the o-AF phase in the superconducting state of underdoped Ba(1-x)K(x)Fe(2)As(2). In agreement with the predicted transition from a single-Q to a double-Q AF structure, we found that a distinct spin density wave develops in the t-AF phase. The pair breaking peak of this spin density wave acquires much more low-energy spectral weight than the one in the o-AF state which indicates that it competes more strongly with superconductivity. We also observed additional phonon modes in the t-AF phase which likely arise from a Brillouin-zone folding that is induced by the double-Q magnetic structure with two Fe sublattices exhibiting different magnitudes of the magnetic moment.

Origin of the tetragonal-to-orthorhombic phase transition in FeSe: a combined thermodynamic and NMR study of nematicity.

The nature of the tetragonal-to-orthorhombic structural transition at T_{s}≈90 K in single crystalline FeSe is studied using shear-modulus, heat-capacity, magnetization, and nuclear magnetic resonance measurements. The transition is shown to be accompanied by a large shear-modulus softening, which is practically identical to that of underdoped Ba(Fe,Co)_{2}As_{2}, suggesting a very similar strength of the electron-lattice coupling. On the other hand, a spin-fluctuation contribution to the spin-lattice relaxation rate is only observed below T_{s}. This indicates that the structural, or "nematic," phase transition in FeSe is not driven by magnetic fluctuations.

Dichotomy between the Hole and Electron Behavior in Multiband Superconductor FeSe Probed by Ultrahigh Magnetic Fields.

Magnetoresistivity ρ(xx) and Hall resistivity ρ(xy) in ultrahigh magnetic fields up to 88 T are measured down to 0.15 K to clarify the multiband electronic structure in high-quality single crystals of superconducting FeSe. At low temperatures and high fields we observe quantum oscillations in both resistivity and the Hall effect, confirming the multiband Fermi surface with small volumes. We propose a novel approach to identify from magnetotransport measurements the sign of the charge carriers corresponding to a particular cyclotron orbit in a compensated metal. The observed significant differences in the relative amplitudes of the quantum oscillations between the ρ(xx) and ρ(xy) components, together with the positive sign of the high-field ρ(xy), reveal that the largest pocket should correspond to the hole band. The low-field magnetotransport data in the normal state suggest that, in addition to one hole and one almost compensated electron band, the orthorhombic phase of FeSe exhibits an additional tiny electron pocket with a high mobility.

Gas-phase electronic transitions of C17H12N⁺ at 15 K.

The electronic spectrum of C17H12N(+), phenanthrene with a side chain, was measured in the gas phase at a vibrational and rotational temperature of ∼15 K in an ion trap using a resonant multiphoton dissociation technique. The C17H12N(+) structure was produced in a chemical ionization source and identified by a comparison with theoretical calculations of stable structures and excitation energies. The (3), (2), (1) (1)A ← X (1)A electronic transitions of this nitrogen-containing aromatic species with 30 atoms have origin band maxima at 23,586 ± 1 cm(-1), 16,120 ± 50 cm(-1), and 14,519 ± 30 cm(-1). Distinct vibrational structure in the (3) (1)A state is observed, and assignments are made. Astronomical aspects are considered.

Transfer of microcystin from freshwater lakes to Puget Sound, WA and toxin accumulation in marine mussels (Mytilus trossulus).

Many eutrophic inland freshwater lakes in the Puget Sound Washington region produce toxic cyanobacteria blooms annually. While such blooms in lakes tend to be viewed as a localized phenomenon, there is significant potential for downstream export of toxins to freshwater streams, and marine and brackish water environments. However, monitoring for cyanotoxins typically associated with freshwaters, such as the hepatotoxin, microcystin (MC) in marine receiving waters is rare. In 2013 we studied four eutrophic Puget Sound area lakes to assess both toxin transport to marine waters and its potential accumulation in marine shellfish, specifically mussels. Shellfish beds are extensive throughout Puget Sound, and recreational harvest occurs downstream of our study lakes, so a study goal was to also assess if shellfish consumption poses a human health risk for MC exposure. We confirm, for the first time, freshwater to marine transfer of MCs in Puget Sound with subsequent bioaccumulation of MC by mussels. ELISA analysis estimated maximum MC concentrations in source lakes of 2700 µg/L, up to 0.34 µg/L in marine waters and 6.5 µg/kg in mussels. Confirmatory analyses by LC-MS/MS on water and mussel samples identified MC-LA as the major toxin. Although we found relatively low MC levels in mussels, our study implies that potential concern for human food safety is justified and warrants further investigation.

Cyanotoxin bioaccumulation in freshwater fish, Washington State, USA.

Until recently, exposure pathways of concern for cyanotoxins have focused on recreational exposure, drinking water, and dermal contact. Exposure to cyanotoxins through fish consumption is a relatively new area of investigation. To address this concern, microcystins and other cyanotoxins were analyzed in fish collected from nine Washington lakes with recurrent toxic blooms using two types of enzyme-linked immunosorbent assays (ELISAs) and liquid chromatography/mass spectrometry/mass spectrometry (LC-MS/MS). Microcystins or microcystin-like compounds were elevated in fish liver relative to muscle and other tissues (liver>gut>muscle). Microcystin concentrations in fish fillet samples using anti-Adda ELISA (range 6.3-11 µg/kg wet weight) were consistently higher in all fish species than concentrations using anti-microcystin (MC)-leucine-arginine (LR) ELISA (range 0.25-2.4 µg/kg wet weight). MC-leucine-alanine (LA) was the only variant detected in fish (2.5-12 µg/kg in four livers) among the nine variants analyzed by LC-MS/MS. Fish fillets showed no accumulation of the MCs targeted by LC-MS/MS. Other cyanotoxins analyzed (anatoxin-a, saxitoxin, domoic acid, and okadaic acid) were not detected in fish. Based on this and evidence from other studies, we believe that people can safely consume two 8-oz fish fillet meals per week from lakes with blooms producing MCs (clean the fish and discard viscera).

Identifying best methods for routine ELISA detection of microcystin in seafood.

Ingestion of water contaminated with the cyanotoxin, microcystin (MC), can pose serious health risks to humans. MC is also known to accumulate in seafood; however, this exposure pathway is much less understood. A fundamental element of this uncertainty is related to analytical difficulties. Commercially available enzyme-linked immunosorbent assays (ELISAs) offer one of the best options for routine MC detection, but methods of detecting MC in tissue are far from standardized. We spiked freshwater finfish and marine mussel tissues with MC, then compared recovery rates using four different preparation protocols and two ELISA types (polyclonal anti-MC-ADDA/direct monoclonal (DM)). Preparation protocol, type of ELISA, and seafood tissue variety significantly affected MC detection. This is the first known study to use DM ELISA for tissue analyses, and our findings demonstrate that DM ELISA combined with a short solvent extraction results in fewer false positives than other commonly used methods. This method can be used for rapid and reliable MC detection in seafood.

Nematic susceptibility of hole-doped and electron-doped BaFe2As2 iron-based superconductors from shear modulus measurements.

The nematic susceptibility, χφ, of hole-doped Ba(1-x)K(x)Fe2As2 and electron-doped Ba(Fe(1-x)Co(x))2As2 iron-based superconductors is obtained from measurements of the elastic shear modulus using a three-point bending setup in a capacitance dilatometer. Nematic fluctuations, although weakened by doping, extend over the whole superconducting dome in both systems, suggesting their close tie to superconductivity. Evidence for quantum critical behavior of χφ is, surprisingly, only found for Ba(Fe(1-x)Co(x))2As2 and not for Ba(1-x)K(x)Fe2As2--the system with the higher maximal Tc value.

Evidence of strong correlations and coherence-incoherence crossover in the iron pnictide superconductor KFe2As2.

Using resistivity, heat-capacity, thermal-expansion, and susceptibility measurements we study the normal-state behavior of KFe2As2. Both the Sommerfeld coefficient (γ≈103 mJ mol(-1) K(-2)) and the Pauli susceptibility (χ≈4×10(-4)) are strongly enhanced, which confirm the existence of heavy quasiparticles inferred from previous de Haas-van Alphen and angle-resolved photoemission spectroscopy experiments. We discuss this large enhancement using a Gutzwiller slave-boson mean-field calculation, which shows the proximity of KFe2As2 to an orbital-selective Mott transition. The temperature dependence of the magnetic susceptibility and the thermal expansion provide strong experimental evidence for the existence of a coherence-incoherence crossover, similar to what is found in heavy fermion and ruthenate compounds, due to Hund's coupling between orbitals.

[Persons held in preventive detention (§ 66 Criminal Code): characteristics of offenders and the impact on prospects for successful completion of therapy]. / Sicherungsverwahrte (§ 66 StGB): Merkmale der Täter und ihre Bedeutung für die Erfolgsaussichten eines therapeutischen Vollzugs.

With its verdict in May 2011 the German Federal Constitutional Court declared the current law for preventive detention unconstitutional and obliged the legislative bodies to undertake a freedom- and treatment-oriented reform. Psychiatrists and psychotherapists are bound to provide therapeutic concepts. Currently there is a lack of information on the intended clientele. In our study we examined 26 persons serving preventive detention, 32 regular prisoners and 29 non-delinquent probands. The groups were matched according to age and intelligence. We gathered sociodemographic data, criminal records and conducted the tests SCID I, SCID II und PCL-R, K-FAF and BIS-11 to obtain diagnoses and characteristics. Based on this information, the HCR-20 and GAF were performed. In comparison to regular prisoners and non-delinquents, the group of those serving preventive detention is characterised by medium to advanced age, antisociality, psychopathy, substance abuse or addiction, aggressivity, a strong criminal record, years of imprisonment, insufficient educational and vocational training and a high risk of recidivism. In our examination of persons serving preventive detention, we demonstrate that this clientele is a group of recidivists difficult to treat. The current laws and a lack of early intervention programs have prevented and delayed their timely and possibly successful treatment. From a psychiatric point of view, there is a strong need for new therapeutic concepts to meet this challenge.

Observation of the non-linear Meissner effect.

A long-standing theoretical prediction is that in clean, nodal unconventional superconductors the magnetic penetration depth λ, at zero temperature, varies linearly with magnetic field. This non-linear Meissner effect is an equally important manifestation of the nodal state as the well studied linear-in-T dependence of λ, but has never been convincingly experimentally observed. Here we present measurements of the nodal superconductors CeCoIn5 and LaFePO which clearly show this non-linear Meissner effect. We further show how the effect of a small dc magnetic field on λ(T) can be used to distinguish gap nodes from non-nodal deep gap minima. Our measurements of KFe2As2 suggest that this material has such a non-nodal state.

[Violent offenders with or without antisocial personality disorder. A comparison]. / Gewaltstraftäter mit und ohne Antisoziale Persönlichkeitsstörung. Ein Vergleich.

BACKGROUND: The influence of legal offences on the diagnosis of antisocial personality disorder (ASPD) is a common discussion. A population of imprisoned delinquents diagnosed with ASPD was compared to delinquents without ASPD concerning sociodemographic, criminological and clinical characteristics to determine if ASPD can differentiate delinquents apart from committing legal offences. PATIENTS AND METHODS: A total of 36 violent offenders with diagnosed ASPD and 29 violent offenders without ASPD were recruited in the prison of Straubing (Germany); 28 control subjects without previous convictions were recruited in the German population. All subjects were examined with the SKID-I and SKID-II, GAF, BIS-11, EPI and K-FAF. RESULTS: Violent offenders with ASPD differ from violent offenders without ASPD concerning the following parameters: high values of impulsivity, aggression, irritability, neuroticism and extraversion; low levels of psychosocial functioning, cumulative "broken home" indicators and antisocial behaviour before the age of 11 ("early starters"). CONCLUSION: Some features are suitable for the discrimination between offenders with or without ADPD, but our results indicate that samples are better distinguished by a dimensional approach, oriented toward their degree of characteristics.

Status of state cyanoHAB outreach and monitoring efforts, United States.

A widespread effort is underway to improve awareness of cyanobacteria harmful algal blooms (cyanoHABs) across the United States using a variety of monitoring programs and public health outreach measures to protect people, pets, and livestock. To determine the status of cyanoHAB outreach and monitoring efforts, 2 questionnaires were distributed to health/environmental departments in 50 states and the District of Columbia (DC). One questionnaire focused on cyanoHAB exposure to humans from drinking water and the second targeted exposure through recreational activities. All states plus DC responded to the recreational survey; 46 states plus DC responded to the drinking water survey. All states except Alaska answered that microcystins were the cyanotoxins of greatest concern for recreational exposure; microcystins were also of greatest concern for drinking water with the exception of Utah (anatoxin-a in reservoirs was greatest concern) and Rhode Island (microcystins and anatoxin-a in reservoirs/ponds were greatest concern). Regional comparisons disclosed a lack of cyanoHAB programs in southern states relative to northern states that may be related to the higher percentage of water surface area in northern states. Interestingly, recreational outreach is more extensive than drinking water outreach (only 16 states reported having some type of drinking water outreach program, compared with 35 states with recreational outreach), and preferred outreach methods are websites and press releases. Additionally, respondents reported very limited funding for outreach and monitoring programs. Our results establish baseline information to help determine what future direction cyanoHAB outreach and monitoring programs can take at local, regional, and national levels.

Prevalence and persistence of microcystin in shoreline lake sediments and porewater, and associated potential for human health risk.

Midlatitude waterbodies are experiencing increased cyanobacteria blooms that necessitate health advisories to protect waterbody users. Although surface waters may contain cyanotoxins such as microcystin (MC), at concentrations that pose potential public health risks, little is known about MC contamination of shoreline sediments. Based on growing evidence that lake and reservoir sediments can accumulate MCs, we hypothesized that shoreline sediments (i.e., recreational beaches) may accumulate MCs and thereby pose a potential health risk to recreational users even if people stay out of contaminated water. We sampled nearshore surface water, shoreline sediment, and porewater from seven Washington State, USA, lakes/reservoirs recreational beaches to determine MC presence/absence during or immediately following cyanobacteria blooms. We found MCs in shoreline sediments at all waterbodies using ELISA and LC-MS/MS. MC concentrations in shoreline sediments and porewaters persisted for 20 days following dissipation of cyanobacteria blooms when MC concentrations were near analytical reporting limits in corresponding surface waters. A human health risk assessment based on potential MC exposure through incidental ingestion of porewaters and sediments found, even when very high MC concentrations occur in surface waters (i.e., >11,000 µg/L), estimated ingestion doses are below MC World Health Organization tolerable daily intake and U.S. Environmental Protection Agency's risk reference dose. While our findings suggest MCs in Washington State recreational beaches in 2018 did not present a significant human health risk, future blooms with higher MC concentrations could pose human health risks via the shoreline sediment/porewater exposure pathway.

Enhancement of the critical temperature of HgBa2CuO(4+δ) by applying uniaxial and hydrostatic pressure: implications for a universal trend in cuprate superconductors.

It is well known that the superconducting transition temperature (T(c)) of cuprate superconductors can be enhanced by varying certain structural and electronic parameters, such as the flatness of the CuO2 planes or their doping level. We determine the uniaxial and hydrostatic pressure derivatives of T(c) in the structurally simple tetragonal compound HgBa2CuO(4+δ) near optimal doping. Our results provide experimental evidence for two further methods to enhance T(c): (i) reducing the area of the CuO2 planes, and (ii) increasing the separation of the CuO2 planar groups. T(c) is found to couple much more strongly to the ratio c/a of the lattice constants than to the unit cell volume. A comparison with prior results for structurally more complicated cuprates reveals a general trend of uniaxial pressure derivatives with T(c).