Dynamic Interactive Social Cognition Training in Virtual Reality (DiSCoVR) versus Virtual Reality Relaxation (VRelax) for People With a Psychotic Disorder: A Single-Blind Multicenter Randomized Controlled Trial.

BACKGROUND AND HYPOTHESIS: Social cognition training (SCT), an intervention for social cognition and social functioning, might be improved by using virtual reality (VR), because VR may offer better opportunities to practice in a potentially more realistic environment. To date, no controlled studies have investigated VR-SCT. This study investigated a VR-SCT, "DiSCoVR". We hypothesized that DiSCoVR would improve social cognition and social functioning. STUDY DESIGN: Participants were randomized to DiSCoVR (n = 41) or VR relaxation ('VRelax', n = 40), an active control condition, and completed 16 twice-weekly sessions. Three assessments (baseline, posttreatment, and 3-month follow-up) were performed by blinded assessors. The primary outcome was social cognition (emotion perception and theory of mind). Secondary outcomes included social functioning (measured with an interview and experience sampling), psychiatric symptoms, information processing, and self-esteem. Data were analyzed using mixed-models regression analysis. Treatment effects were evaluated by the time by condition interaction terms. STUDY RESULTS: No significant time by condition interactions were found for any of the outcome variables, indicating an absence of treatment effects. Between-group effect sizes ranged from negligible to moderate (Cohen's d < |0.53|). Main effects of time were found for several outcomes. CONCLUSIONS: These results suggest that DiSCoVR was not effective, possibly because of inadequate simulation of emotional expressions in VR. This lack of efficacy may indicate that current SCT protocols are relatively unsuitable for improving social functioning. Previous studies showed small to moderate effects on higher order social cognition, but the SCT approach may need critical reevaluation, as it may not sufficiently lead to functional improvement.

Long-term immunogenicity after yellow fever vaccination in immunosuppressed and healthy individuals.

BACKGROUND: The live-attenuated yellow fever vaccine (YFV) is generally contraindicated in immunosuppressed patients. Our aim was to investigate if immunosuppressive therapy impairs the long-term protection against yellow fever virus in patients who had received YFV prior to the start of their immunosuppressive therapy. METHODS: Our study examined 35 healthy individuals and 40 immunosuppressed patients with autoimmune diseases or organ transplants. All individuals had received YFV prior to the onset of their immunosuppression. We analysed the long-term influence of the immunosuppressive therapy on the YFV protective immunity by measuring neutralising antibodies (NA) with the Plaque Reduction Neutralisation Test (PRNT). We assessed risk factors for a negative PRNT result (titre below 1: 10) and their influence on the magnitude of the NA. RESULTS: A median time interval of 21.1 years (interquartile range 14.4-31.3 years) after the YFV in all patients, a total of 35 immunosuppressed patients (88%) were seropositive (PRNT ≥ 1:10) compared to 31 patients (89%) in the control group. The geometric mean titres of NA did not differ between the groups. The duration of an underlying rheumatic disease was the only risk factor found for a lower magnitude of NA. An insufficient level of NA was found in nine subjects (12%) who had received a single dose of YFV (in one subject, the number of YFV doses was unknown). CONCLUSION: The use of an immunosuppressive drug started after the administration of the YFV did not affect long-term persistence of NA. A second dose of YFV may be necessary to secure long-term immunity.

Superconductivity under pressure in the Dirac semimetal PdTe2.

The Dirac semimetal PdTe2 was recently reported to be a type-I superconductor (T c = 1.64 K, [Formula: see text] mT) with unusual superconductivity of the surface sheath. We here report a high-pressure study, [Formula: see text] GPa, of the superconducting phase diagram extracted from ac-susceptibility and transport measurements on single crystalline samples. T c (p ) shows a pronounced non-monotonous variation with a maximum T c = 1.91 K around 0.91 GPa, followed by a gradual decrease to 1.27 K at 2.5 GPa. Surface superconductivity is robust under pressure as demonstrated by the large superconducting screening signal that persists for applied dc-fields [Formula: see text]. Surprisingly, for [Formula: see text] GPa the superconducting transition temperature at the surface [Formula: see text] is larger than T c of the bulk. Therefore surface superconductivity may possibly have a non-trivial topological nature. We compare the measured pressure variation of T c with recent results from band structure calculations and discuss the importance of a Van Hove singularity.

Penetration depth study of the type-I superconductor PdTe2.

Superconductivity in the topological non-trivial Dirac semimetal PdTe2 was recently shown to be type-I. We hereby report measurements of the relative magnetic penetration depth, [Formula: see text], on several single crystals using a high precision tunnel diode oscillator technique. The temperature variation [Formula: see text] follows an exponential function for [Formula: see text], consistent with a fully-gapped superconducting state and weak or moderately coupling superconductivity. By fitting the data we extract a [Formula: see text]-value of ∼500 nm. The normalized superfluid density is in good agreement with the computed curve for a type-I superconductor with nonlocal electrodynamics. Small steps are observed in [Formula: see text], which possibly relates to a locally lower [Formula: see text] due to defects in the single crystalline sample.

Rotational symmetry breaking in the topological superconductor SrxBi2Se3 probed by upper-critical field experiments.

Recently it was demonstrated that Sr intercalation provides a new route to induce superconductivity in the topological insulator Bi2Se3. Topological superconductors are predicted to be unconventional with an odd-parity pairing symmetry. An adequate probe to test for unconventional superconductivity is the upper critical field, Bc2. For a standard BCS layered superconductor Bc2 shows an anisotropy when the magnetic field is applied parallel and perpendicular to the layers, but is isotropic when the field is rotated in the plane of the layers. Here we report measurements of the upper critical field of superconducting SrxBi2Se3 crystals (Tc = 3.0 K). Surprisingly, field-angle dependent magnetotransport measurements reveal a large anisotropy of Bc2 when the magnet field is rotated in the basal plane. The large two-fold anisotropy, while six-fold is anticipated, cannot be explained with the Ginzburg-Landau anisotropic effective mass model or flux flow induced by the Lorentz force. The rotational symmetry breaking of Bc2 indicates unconventional superconductivity with odd-parity spin-triplet Cooper pairs (Δ4-pairing) recently proposed for rhombohedral topological superconductors, or might have a structural nature, such as self-organized stripe ordering of Sr atoms.

17D yellow fever vaccine elicits comparable long-term immune responses in healthy individuals and immune-compromised patients.

BACKGROUND: The 17D live attenuated yellow fever (YF) vaccine is contra-indicated in immune-compromised individuals and may elicit a suboptimal immunologic response. The aim of this study is to assess whether long-term immune responses against the YF vaccine are impaired in immune-compromised patients. MATERIALS AND METHODS: Fifteen patients using different immunosuppressive drugs and 30 healthy individuals vaccinated 0-22 years ago were included. The serological response was measured using the plaque reduction neutralization test (PRNT). CD8(+) and CD4(+) T-cell responses were measured following proliferation and re-stimulation with YFV peptide pools. Phenotypic characteristics and cytokine responses of CD8(+) T-cells were determined using class I tetramers. RESULTS: The geometric mean titre of neutralizing antibodies was not different between the groups (p = 0.77). The presence of YFV-specific CD4(+) and CD8(+) T-cell did not differ between patients and healthy individuals (15/15, 100.0% vs. 29/30, 96.7%, p = 0.475). Time since vaccination correlated negatively with the number of YFV-specific CD8(+) T-cells (r = -0.66, p = 0.0045). Percentages of early-differentiated memory cells increased (r = 0.67, p = 0.017) over time. CONCLUSION: These results imply that YF vaccination is effective despite certain immunosuppressive drug regimens. An early-differentiated memory-like phenotype persisted, which is associated with effective expansion upon re-encounter with antigen, suggesting a potent memory T-cell pool remains.

Micro-metric electronic patterning of a topological band structure using a photon beam.

In an ideal 3D topological insulator (TI), the bulk is insulating and the surface conducting due to the existence of metallic states that are localized on the surface; these are the topological surface states. Quaternary Bi-based compounds of Bi(2-x)Sb(x)Te(3-y)Se(y) with finely-tuned bulk stoichiometries are good candidates for realizing ideal 3D TI behavior due to their bulk insulating character. However, despite its insulating bulk in transport experiments, the surface region of Bi(2-x)Sb(x)Te(3-y)Se(y) crystals cleaved in ultrahigh vacuum also exhibits occupied states originating from the bulk conduction band. This is due to adsorbate-induced downward band-bending, a phenomenon known from other Bi-based 3D TIs. Here we show, using angle-resolved photoemission, how an EUV light beam of moderate flux can be used to exclude these topologically trivial states from the Fermi level of Bi1.46Sb0.54Te1.7Se1.3 single crystals, thereby re-establishing the purely topological character of the low lying electronic states of the system. We furthermore prove that this process is highly local in nature in this bulk-insulating TI, and are thus able to imprint structures in the spatial energy landscape at the surface. We illustrate this by 'writing' micron-sized letters in the Dirac point energy of the system.

Magnetic and superconducting phase diagram of the half-Heusler topological semimetal HoPdBi.

We report a study of the magnetic and electronic properties of the non-centrosymmetric half-Heusler antiferromagnet HoPdBi (TN = 2.0 K). Magnetotransport measurements show HoPdBi has a semimetallic behavior with a carrier concentration n = 3.7 × 10(18) cm(-3) extracted from the Shubnikov-de Haas effect. The magnetic phase diagram in the field-temperature plane has been determined by transport, magnetization, and thermal expansion measurements: magnetic order is suppressed at BM ~ 3.6 T for T --> 0. Superconductivity with Tc ~ 1.9 K is found in the antiferromagnetic phase. Ac-susceptibility measurements provide solid evidence for bulk superconductivity below Tc = 0.75 K with a screening signal close to a volume fraction of 100%. The upper critical field shows an unusual linear temperature variation with Bc2(T --> 0) = 1.1 T. We also report electronic structure calculations that classify HoPdBi as a new topological semimetal, with a non-trivial band inversion of 0.25 eV.

Superconductivity in the doped topological insulator Cu{x}Bi{2}Se{3} under high pressure.

We report a high-pressure single crystal study of the topological superconductor Cu{x}Bi{2}Se{3}. Resistivity measurements under pressure show superconductivity is depressed smoothly. At the same time the metallic behavior is gradually lost. The upper-critical field data B{c2}(T) under pressure collapse onto a universal curve. The absence of Pauli limiting and the comparison of B{c2}(T) to a polar-state function point to spin-triplet superconductivity, but an anisotropic spin-singlet state cannot be discarded completely.

Single-crystal study on the heavy-fermion antiferromagnet UZn12.

Millimetre size UZn(12) single crystals were grown by the high temperature solution growth method using zinc as the solvent. Single-crystal x-ray diffraction data confirm that this compound crystallizes in the hexagonal high temperature form of SmZn(12) (S.G. P6/mmm) and points to a U(1.01(1))Zn(11.7(1)) stoichiometry for the crystals, with ∼ 4% of the U atoms being located at the 2c site due to the partial substitution of 4h Zn pairs. UZn(12) orders antiferromagnetically at T(N) = 5.0(2) K, and the magnetization and resistivity measurements suggest that the magnetic moments are confined within the a-b plane. The Sommerfeld coefficient, derived from the paramagnetic region by the standard method, is γ(p)≈200 mJ (mol K(2))( - 1), which definitely classifies UZn(12) as a moderate heavy-fermion system. The heavy-fermion character of UZn(12) is also manifested in the overall shape of temperature-dependent electrical resistivity that is dominated by a single-ion Kondo effect at high temperatures and coherent Kondo scattering at low temperatures. The paramagnetic magnetoresistivity isotherms can be fairly well superimposed onto each other using Schlottmann's scaling for the single-ion Kondo model, as expected for a Kondo system.

Enhancement of superconductivity near the ferromagnetic quantum critical point in UCoGe.

We report a high-pressure single crystal study of the superconducting ferromagnet UCoGe. Measurements of the ac susceptibility and resistivity under pressures up to 2.2 GPa show ferromagnetism is smoothly depressed and vanishes at a critical pressure p(c) = 1.4 GPa. Near the ferromagnetic critical point superconductivity is enhanced. Upper-critical field measurements under pressure show B(c2)(0) attains remarkably large values, which provides solid evidence for spin-triplet superconductivity over the whole pressure range. The obtained p-T phase diagram reveals superconductivity is closely connected to a ferromagnetic quantum-critical point hidden under the superconducting "dome."

Muon spin rotation and relaxation in the superconducting ferromagnet UCoGe.

We report zero-field muon-spin rotation and relaxation measurements on the superconducting ferromagnet UCoGe. Weak itinerant ferromagnetic order is detected by a spontaneous muon-spin precession frequency below the Curie temperature TC=3 K. The micro+ precession frequency persists below the bulk superconducting transition temperature Tsc=0.5 K, where it measures a local magnetic field Bloc=0.015 T. The amplitude of the microSR signal provides unambiguous proof for ferromagnetism present in the whole sample volume. We conclude ferromagnetism coexists with superconductivity on the microscopic scale.

Operative treatment of acute Achilles tendon rupture: Open end-to-end-reconstruction versus reconstruction with Mitek-anchors.

PURPOSE: To retrospectively compare the open end-to-end repair versus repair using the Mitek-anchor system in acute Achilles tendon rupture. METHOD: Forty-seven consecutive patients with Achilles tendon rupture, all operated on between 2004 and 2005, were included. Their medical records were reviewed and they were interviewed for surveillance of post-operative function at follow-up. Functional outcome was determined using an adapted VISA tendinopathy questionnaire and by testing the isometric ankle plantar flexion strength. Post-operative complications and recurrence rate of rupture were noted. RESULTS: Seven patients were lost to follow-up. From a total of 40 patients, twenty-eight (68% of total) underwent classic repair and 12 (32%) were treated by the Mitek-anchor system. Median age was 43 years (range 29-63). Median post-operative follow-up was 29 months (range 17-40). Median time to resume work was nine weeks in the classic group versus 12 weeks in the Mitek-group. Median time to resume sports was 19 versus 31 weeks respectively. Wound infections occurred in five percent of the total (one in each group) and rupture recurrence rate was three percent of the total (nil in classic group, one in Mitek-group). Loss of strength in the injured leg compared to the non-injured leg was greater in the Mitek-group than in the classic group. CONCLUSION: We conclude that in comparing classical end-to-end repair of acute Achilles tendon ruptures with repair using Mitek-anchors, it took patients in the Mitek-group longer to return to work and sport activities than in the classic group. Greater loss of strength in the injured leg was seen in the Mitek-group. Therefore we do not advocate the use of Mitek-anchors for the repair of acute ruptured Achilles tendons.

Unusual upper critical field of the ferromagnetic superconductor UCoGe.

We report upper critical field B(c2)(T) measurements on a single-crystalline sample of the ferromagnetic superconductor UCoGe. B(c2)(0) obtained for fields applied along the orthorhombic axes exceeds the Pauli limit for B parallela,b and shows a strong anisotropy B(c2)(a) approximately B(c2)(b)>>B(c2)(c). This provides evidence for an equal-spin pairing state and a superconducting gap function of axial symmetry with point nodes along the c axis, which is also the direction of the uniaxial ferromagnetic moment m(0)=0.07micro(B). An unusual curvature or kink is observed in the temperature variation of B(c2) which possibly indicates UCoGe is a two-band ferromagnetic superconductor.

Superconductivity on the border of weak itinerant ferromagnetism in UCoGe.

We report the coexistence of ferromagnetic order and superconductivity in UCoGe at ambient pressure. Magnetization measurements show that UCoGe is a weak ferromagnet with a Curie temperature T(C)=3 K and a small ordered moment m(0)=0.03 micro(B). Superconductivity is observed with a resistive transition temperature T(s)=0.8 K for the best sample. Thermal-expansion and specific-heat measurements provide solid evidence for bulk magnetism and superconductivity. The proximity to a ferromagnetic instability, the defect sensitivity of T(s), and the absence of Pauli limiting, suggest triplet superconductivity mediated by critical ferromagnetic fluctuations.

Role of genomic typing in taxonomy, evolutionary genetics, and microbial epidemiology.

Currently, genetic typing of microorganisms is widely used in several major fields of microbiological research. Taxonomy, research aimed at elucidation of evolutionary dynamics or phylogenetic relationships, population genetics of microorganisms, and microbial epidemiology all rely on genetic typing data for discrimination between genotypes. Apart from being an essential component of these fundamental sciences, microbial typing clearly affects several areas of applied microbiological research. The epidemiological investigation of outbreaks of infectious diseases and the measurement of genetic diversity in relation to relevant biological properties such as pathogenicity, drug resistance, and biodegradation capacities are obvious examples. The diversity among nucleic acid molecules provides the basic information for all fields described above. However, researchers in various disciplines tend to use different vocabularies, a wide variety of different experimental methods to monitor genetic variation, and sometimes widely differing modes of data processing and interpretation. The aim of the present review is to summarize the technological and fundamental concepts used in microbial taxonomy, evolutionary genetics, and epidemiology. Information on the nomenclature used in the different fields of research is provided, descriptions of the diverse genetic typing procedures are presented, and examples of both conceptual and technological research developments for Escherichia coli are included. Recommendations for unification of the different fields through standardization of laboratory techniques are made.

Evidence for a two component magnetic response in UPt3

The magnetic response of the heavy fermion superconductor UPt3 has been investigated on a microscopic scale by muon Knight shift studies. Two distinct and isotropic Knight shifts have been found for the field in the basal plane. While the volume fractions associated with the two Knight shifts are approximately equal at low and high temperatures, they show a dramatic and opposite temperature dependence around T(N). Our results are independent on the precise muon localization site. We conclude that UPt3 is characterized by a two component magnetic response.

Probing the plateau-insulator quantum phase transition in the quantum hall regime

We report quantum Hall experiments on the plateau-insulator transition in a low mobility In(0.53)Ga(0.47)As/InP heterostructure. The data for the longitudinal resistance rho(xx) follow an exponential law and we extract a critical exponent kappa = 0.55+/-0. 05 which is slightly different from the established value kappa = 0. 42+/-0.04 for the plateau transitions. Upon correction for inhomogeneity effects, which cause the critical conductance sigma(*)(xx) to depend marginally on temperature, our data indicate that the plateau-plateau and plateau-insulator transitions are in the same universality class.