1,618 research outputs found
Highly nonperturbative nature of the Mott metal-insulator transition: Two-particle vertex divergences in the coexistence region
We thoroughly analyze the divergences of the irreducible vertex functions
occurring in the charge channel of the half-filled Hubbard model in close
proximity to the Mott metal-insulator transition (MIT). In particular, by
systematically performing dynamical mean-field theory (DMFT) calculations on
the two-particle level, we determine the location and the number of the vertex
divergences across the whole coexistence region adjacent to the first-order
metal-to-insulator transition. We find that the lines in the parameter space,
along which the vertex divergences occur, display a qualitatively different
shape in the coexisting metallic and insulating phase, which is also associated
to an abrupt jump of the number of divergences across the MIT. Physically, the
systematically larger number of divergences on the insulating side of the
transition reflects the sudden suppression of local charge fluctuation at the
MIT. Further, a systematic analysis of the results demonstrates that the number
of divergence lines increases as a function of the inverse temperature
by approaching the Mott transition in the
zero temperature limit. This makes it possible to identify the zero-temperature
MIT as an accumulation point of an infinite number of vertex divergence lines,
unveiling the highly nonperturbative nature of the underlying transition.Comment: 16 pages, 12 figure
Depersonalization disorder : disconnection of cognitive evaluation from autonomic responses to emotional stimuli
BACKGROUND: Patients with depersonalization disorder (DPD) typically complain about emotional detachment. Previous studies found reduced autonomic responsiveness to emotional stimuli for DPD patients as compared to patients with anxiety disorders. We aimed to investigate autonomic responsiveness to emotional auditory stimuli of DPD patients as compared to patient controls. Furthermore, we examined the modulatory effect of mindful breathing on these responses as well as on depersonalization intensity.
METHODS: 22 DPD patients and 15 patient controls balanced for severity of depression and anxiety, age, sex and education, were compared regarding 1) electrodermal and heart rate data during a resting period, and 2) autonomic responses and cognitive appraisal of standardized acoustic affective stimuli in two conditions (normal listening and mindful breathing).
RESULTS: DPD patients rated the emotional sounds as significantly more neutral as compared to patient controls and standardized norm ratings. At the same time, however, they responded more strongly to acoustic emotional stimuli and their electrodermal response pattern was more modulated by valence and arousal as compared to patient controls. Mindful breathing reduced severity of depersonalization in DPD patients and increased the arousal modulation of electrodermal responses in the whole sample. Finally, DPD patients showed an increased electrodermal lability in the rest period as compared to patient controls.
CONCLUSIONS: These findings demonstrated that the cognitive evaluation of emotional sounds in DPD patients is disconnected from their autonomic responses to those emotional stimuli. The increased electrodermal lability in DPD may reflect increased introversion and cognitive control of emotional impulses. The findings have important psychotherapeutic implications
Is that me in the mirror? Depersonalisation modulates tactile mirroring mechanisms
Our sense of self is thought to develop through sensory-motor contingencies provided, not only by observing one's own body, but also by mirroring interactions with others. This suggests that there is a strong link between mirroring mechanisms and the bodily self. The present study tested whether this link is expressed at early, implicit stages of the mirroring process or at later, more cognitive stages. We also provide, to the best of our knowledge, the first demonstration of how inter-individual differences in our sense of bodily self may affect mirroring mechanisms. We used somatosensory event-related potentials (SEPs) to investigate the temporal dynamics of mirroring highly self-related information (viewed touch on one's own face) compared to other-related information (viewed touch on a stranger's face), in individuals with low and high levels of depersonalisation, a mental condition characterised by feeling detached or estranged from one's self and body. For the low-depersonalisation group, mirroring for self-related events (P45) preceded mirroring for other-related events (N80). At later stages (P200), mirroring was stronger for other-related than self-related events. This shows that early, implicit and later, more cognitive processes play different relative roles in mirroring self- and other-related bodily events. Critically, mirroring differed in the high-depersonalisation group, specifically for self-related events. An absence of early, implicit mirroring for self-related events over P45 suggests that the associated processes may be the neural correlates of the disembodiment experienced in depersonalisation. A lack of differential mirroring for self- and other-related events over P200 may reflect compensatory mechanisms that redress deficiencies in mirroring at earlier stages, which may break down to give rise to symptoms of depersonalisation. Alternatively, or in addition, they may represent an attenuation of processes related to self-other distinction. Our study thus shows that mirroring, especially for events on one's own face, can be strongly affected by how connected the observer feels to their own bodily self
Spatial effects on competition between the larval parasitoids Habrobracon hebetor (Say) (Hymenoptera: Braconidae) and Venturia canescens (Gravenhorst) (Hymenoptera: Ichneumonidae) parasitising the Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae)
Die Larvalparasitoide Venturia canescens (Gravenhorst) und Habrobracon hebetor (Say) sind Parasitoide der Mehlmotte Ephestia kuehniella, der Dörrobstmotte Plodia interpunctella und der Tropischen Speichermotte E. cautella. H. hebetor ist ein idiobionter, gregĂ€rer Ektoparasitoid, d.h. die Wirtslarve wird vor der Eiablage paralysiert und mehrere Nachkommen entwickeln sich an einem Wirtstier (Hase, 1922). V. canescens ist ein koinobionter, solitĂ€rer Endoparasitoid, d.h. die Wirtslarve wird vor der Eiablage nicht paralysiert und nur ein Nachkomme entwickelt sich in einem Wirtstier, welches erst kurz vor der Verpuppung eingeht (1937). Press & al. (1977) zeigten in Versuchen in kleinen VersuchsgefĂ€Ăen, dass V. canescens vollstĂ€ndig von H. hebetor unterdrĂŒckt wurde. Da bereits von V. parasitierte Larven von H.paralysiert und anschlieĂend parasitiert wurden, konnte sich der Nachwuchs von V.nicht entwickeln. V.ihrerseits war nicht in der Lage, bereits von H.paralysierte Larven zu parasitieren. Press & al. (1977) schlussfolgerten daraus, dass V. canescens bei einer massenweisen Freilassung von H. hebetor zur biologischen BekĂ€mpfung unter Praxisbedingungen verdrĂ€ngt werden wĂŒrde. Dennoch treten beide Parasitoide in MĂŒhlen, BĂ€ckereien und LagerhĂ€usern in Mitteleuropa auch bei einem Einsatz von H. hebetor zur biologischen BekĂ€mpfung gemeinsam auf (Prozell & Schoeller, 1998; Lukas, 2002, Prozell & unveröffentl. Daten). Eine mögliche ErklĂ€rung könnte die bessere WirtsfindungsfĂ€higkeit von V. canescens in gröĂeren RĂ€umen sein. Das Wirtsfindungsvermögen beider Arten wurde bereits in einigen Arbeiten behandelt (Parra & Al., 1996; Desouhant & 2005), jedoch wurden die Auswirkungen auf die Konkurrenz dabei nicht betrachtet. Das Ziel dieser Arbeit war es daher, die rĂ€umliche Konkurrenz zwischen H. hebetor und V. canescens in RĂ€umen mit zunehmendem Volumen zu untersuchen.The Mediterranean flour moth Ephestia kuehniella (Lepidoptera: Pyralidae) is a suitable host for the hymenopteran parasitoids Habrobracon hebetor (Hymenoptera: Braconidae) and Venturia canescens (Hymenoptera: Ichneumonidae). These two larval parasitoids differ in the following biological traits: H. hebetor is an idiobiontic, gregarious ectoparasitoid, and V. canescens is a koinobiontic, solitary endoparasitoid. Previous laboratory data obtained in small-scale experiments (Petri-dish) showed that moth larvae parasitised by V. canescens were paralysed by H. hebetor, i.e. the latter parasitoid out-competed V. canescens completely. However, field observations in Central European bakeries and mills showed that both species occur simultaneously. Moreover, V. canescens seems to be more common than H. hebetor in these stored-product environments harbouring populations of E. kuehniella. These observations led to the hypothesis that spatial scale affects the competition between the two parasitoids. Keeping the host-parasitoids ratios constant, experimental chambers with three different volumes were tested, with a maximum volume of 8m3. Hosts were exposed in four patches per room. In trials conducted in small boxes, the increase of parasitism by increasing numbers of female H. hebetor was confirmed. It was shown that the presence of V. canescens did not affect parasitism by H. hebetor under these conditions. With increasing numbers of female H. hebetor in the box, the numbers of emerging adult E. kuehniella decreased. The additional presence of V. canescens drastically reduced the numbers of E. kuehniella emerging in all trials. Spatial effects on competition were detected by comparison of experimental boxes and cages with different volumes. With increasing volume, the percentage of V. canescens emerging was constant, and the number of H. hebetor progeny was decreasing. Patch exploitation was decreasing in H. hebetor with increasing volume, but not in V. canescens. The data suggest that V. canescens is more competitive in large rooms where H. hebetor fails to completely find and exploit host patches
Expression Analysis of Fibronectin Type III Domain-Containing (FNDC) Genes in Inflammatory Bowel Disease and Colorectal Cancer
Background. Fibronectin type III domain-containing (FNDC) proteins fulfill manifold functions in tissue development and regulation of cellular metabolism. FNDC4 was described as anti-inflammatory factor, upregulated in inflammatory bowel disease (IBD). FNDC signaling includes direct cell-cell interaction as well as release of bioactive peptides, like shown for FNDC4 or FNDC5. The G-protein-coupled receptor 116 (GPR116) was found as a putative FNDC4 receptor. We here aim to comprehensively analyze the mRNA expression of FNDC1, FNDC3A, FNDC3B, FNDC4, FNDC5, and GPR116 in nonaffected and affected mucosal samples of patients with IBD or colorectal cancer (CRC). Methods. Mucosa samples were obtained from 30 patients undergoing diagnostic colonoscopy or from surgical resection of IBD or CRC. Gene expression was determined by quantitative real-time PCR. In addition, FNDC expression data from publicly available Gene Expression Omnibus (GEO) data sets (GDS4296, GDS4515, and GDS5232) were analyzed. Results. Basal mucosal expression revealed higher expression of FNDC3A and FNDC5 in the ileum compared to colonic segments. FNDC1 and FNDC4 were significantly upregulated in IBD. None of the investigated FNDCs was differentially expressed in CRC, just FNDC3A trended to be upregulated. The GEO data set analysis revealed significantly downregulated FNDC4 and upregulated GPR116 in microsatellite unstable (MSI) CRCs. The expression of FNDCs and GPR116 was independent of age and sex. Conclusions. FNDC1 and FNDC4 may play a relevant role in the pathobiology of IBD, but none of the investigated FNDCs is regulated in CRC. GPR116 may be upregulated in advanced or MSI CRC. Further studies should validate the altered FNDC expression results on protein levels and examine the corresponding functional consequences
High-resolution fully coupled atmospheric-hydrological modeling: a cross-compartment regional water and energy cycle evaluation
Abstract. The land surface and the atmospheric boundary layer are closely intertwined with respect to the exchange of water, trace gases, and energy. Nonlinear feedback and scale-dependent mechanisms are obvious by observations and theories. Modeling instead is often narrowed to single compartments of the terrestrial system or bound to traditional viewpoints of definite scientific disciplines. Coupled terrestrial hydrometeorological modeling systems attempt to overcome these limitations to achieve a better integration of the processes relevant for regional climate studies and local-area weather prediction. This study examines the ability of the hydrologically enhanced version of the Weather Research and Forecasting model (WRF-Hydro) to reproduce the regional water cycle by means of a two-way coupled approach and assesses the impact of hydrological coupling with respect to a traditional regional atmospheric model setting. It includes the observation-based calibration of the hydrological model component (offline WRF-Hydro) and a comparison of the classic WRF and the fully coupled WRF-Hydro models both with identically calibrated parameter settings for the land surface model (Noah-Multiparametrization; Noah-MP). The simulations are evaluated based on extensive observations at the Terrestrial Environmental Observatories (TERENO) Pre-Alpine Observatory for the Ammer (600âkm2) and Rott (55âkm2) river catchments in southern Germany, covering a 5-month period (JuneâOctober 2016).
The sensitivity of seven land surface parameters is tested using the Latin-HypercubeâOne-factor-At-a-Time (LH-OAT) method, and six sensitive parameters are subsequently optimized for six different subcatchments, using the model-independent Parameter Estimation and Uncertainty Analysis software (PEST).
The calibration of the offline WRF-Hydro gives NashâSutcliffe efficiencies between 0.56 and 0.64 and volumetric efficiencies between 0.46 and 0.81 for the six subcatchments. The comparison of the classic WRF and fully coupled WRF-Hydro models, both using the calibrated parameters from the offline model, shows only tiny alterations for radiation and precipitation but considerable changes for moisture and heat fluxes. By comparison with TERENO Pre-Alpine Observatory measurements, the fully coupled model slightly outperforms the classic WRF model with respect to evapotranspiration, sensible and ground heat flux, the near-surface mixing ratio, temperature, and boundary layer profiles of air temperature. The subcatchment-based water budgets show uniformly directed variations for evapotranspiration, infiltration excess and percolation, whereas soil moisture and precipitation change randomly
A method for acoustic storage pest detection and its challenges
Insekten im Getreide sind ein Problem, nicht nur, weil sie das Getreide fressen, sondern weil sie durch Massenvermehrung mit ihrem Stoffwechsel dazu fĂŒhren, dass WĂ€rme und Feuchte und damit ein guter Lebensraum fĂŒr Schimmel entsteht, der das Getreide unbrauchbar macht. So droht die Kontamination mit Mykotoxinen. Daher ist es wichtig, Insektenbefall frĂŒhzeitig zu erkennen und zu bekĂ€mpfen. Mit dem "Beetle Sound Tube" wurde ein System zur akustischen FrĂŒherkennung von Insekten in Getreide entwickelt, mit dem es möglich ist auch sehr geringen Insektenbefall akustisch zu erfassen und den Lagerhalter per E-Mail zu benachrichtigen. Das System befindet sich wĂ€hrend der Lagerperiode dauerhaft im Getreide und ĂŒberwacht das Getreide auf InsektengerĂ€usche. WĂ€hrend der Entwicklung dieses akustischen Monitoringsystems ergaben sich unterschiedliche Herausforderungen bei der Analyse der sehr leisen InsektengerĂ€usche in einer Umgebung mit vielfĂ€ltigen HintergrundgerĂ€uschen. Auch anfallendes Datenvolumen und Analysegeschwindigkeit mussten optimiert werden, um Befall âjust-in-timeâ erfassen zu können. Das Akustik-Röhrensystem wurde fĂŒr Silos, FlachlĂ€ger und big bags entwickelt und ist damit fĂŒr viele Lagerformen geeignet.Insects in grain can cause serious problems, not only because they feed on the grains. Mass reproduction also causes additional moisture and heat due to the insects' metabolism. This leads to favourable conditions for moulds, which can cause major losses and the formation of mycotoxins. It is therefore important to detect and treat an infestation at an early stage. The "Beetle Sound Tube" system was developed as an acoustic early detection system for insects in grain, which makes it possible to detect even very low levels of infestation and inform the storekeeper by e-mail. The acoustic system remains in the grain during the storage period, and permanently records insect sounds. Challenges were encountered in the development of this acoustic monitoring system, such as analysing very quiet insect sounds in a noisy agricultural environment. In addition, the amount of data collected and the speed of analysis had to be optimised to achieve just-in-time detection of insects. The acoustic tube system was developed for silos, flat stores and big bags and is therefore widely applicable
Magnetic Field Dependence of Muonium-antimuonium Conversion
We study the magnetic field dependence of muonium--antimuonium conversion
induced by neutral (pseudo)scalar bosons. Only the operator contributes to
the conversion of polarized muonium, but it gets quenched by a magnetic field
of strength 0.1 Gauss or stronger. Conversion induced by couplings for
unpolarized muonium is independent of magnetic field. Magnetic fields of 0.1
Tesla or stronger starts to suppress conversion induced by interactions in
the lowest Breit-Rabi level, but gets partially compensated by a rise in
conversion probability in the other unpolarized level. The effects of and operators behave in the same way as and operators, respectively.Comment: 12 pages, ReVtex, 5 figures available upon reques
- âŠ