Bifurcations and bistability in cavity assisted photoassociation of Bose-Einstein condensed molecules

We study the photo-association of Bose-Einstein condensed atoms into molecules using an optical cavity field. The driven cavity field introduces a new dynamical degree of freedom into the photoassociation process, whose role in determining the stationary behavior has not previously been considered. The semiclassical stationary solutions for the atom and molecules as well as the intracavity field are found and their stability and scaling properties are determined in terms of experimentally controllable parameters including driving amplitude of the cavity and the nonlinear interactions between atoms and molecules. For weak cavity driving, we find a bifurcation in the atom and molecule number occurs that signals a transition from a stable steady state to nonlinear Rabi oscillations. For a strongly driven cavity, there exists bistability in the atom and molecule number

Brain mechanisms underlying cue-based memorizing during free viewing of movie Memento

How does the human brain recall and connect relevant memories with unfolding events? To study this, we presented 25 healthy subjects, during functional magnetic resonance imaging, the movie 'Memento' (director C. Nolan). In this movie, scenes are presented in chronologically reverse order with certain scenes briefly overlapping previously presented scenes. Such overlapping "key-frames" serve as effective memory cues for the viewers, prompting recall of relevant memories of the previously seen scene and connecting them with the concurrent scene. We hypothesized that these repeating key-frames serve as immediate recall cues and would facilitate reconstruction of the story piece-by-piece. The chronological version of Memento, shown in a separate experiment for another group of subjects, served as a control condition. Using multivariate event-related pattern analysis method and representational similarity analysis, focal fingerprint patterns of hemodynamic activity were found to emerge during presentation of key-frame scenes. This effect was present in higher-order cortical network with regions including precuneus, angular gyrus, cingulate gyrus, as well as lateral, superior, and middle frontal gyri within frontal poles. This network was right hemispheric dominant. These distributed patterns of brain activity appear to underlie ability to recall relevant memories and connect them with ongoing events, i.e., "what goes with what" in a complex story. Given the real-life likeness of cinematic experience, these results provide new insight into how the human brain recalls, given proper cues, relevant memories to facilitate understanding and prediction of everyday life events.Peer reviewe

Lipreading and Covert Speech Production Similarly Modulate Human Auditory-Cortex Responses to Pure Tones

Watching the lips of a speaker enhances speech perception. At the same time, the 100 ms response to speech sounds is suppressed in the observer's auditory cortex. Here, we used whole-scalp 306-channel magnetoencephalography (MEG) to study whether lipreading modulates human auditory processing already at the level of the most elementary sound features, i.e., pure tones. We further envisioned the temporal dynamics of the suppression to tell whether the effect is driven by top-down influences. Nineteen subjects were presented with 50 ms tones spanning six octaves (125–8000 Hz) (1) during “lipreading,” i.e., when they watched video clips of silent articulations of Finnish vowels /a/, /i/, /o/, and /y/, and reacted to vowels presented twice in a row; (2) during a visual control task; (3) during a still-face passive control condition; and (4) in a separate experiment with a subset of nine subjects, during covert production of the same vowels. Auditory-cortex 100 ms responses (N100m) were equally suppressed in the lipreading and covert-speech-production tasks compared with the visual control and baseline tasks; the effects involved all frequencies and were most prominent in the left hemisphere. Responses to tones presented at different times with respect to the onset of the visual articulation showed significantly increased N100m suppression immediately after the articulatory gesture. These findings suggest that the lipreading-related suppression in the auditory cortex is caused by top-down influences, possibly by an efference copy from the speech-production system, generated during both own speech and lipreading.Peer reviewe

Mental Action Simulation Synchronizes Action-Observation Circuits across Individuals

A frontoparietal action–observation network (AON) has been proposed to support understanding others' actions and goals. We show that the AON "ticks together" in human subjects who are sharing a third person's feelings. During functional magnetic resonance imaging, 20 volunteers watched movies depicting boxing matches passively or while simulating a prespecified boxer's feelings. Instantaneous intersubject phase synchronization (ISPS) was computed to derive multisubject voxelwise similarity of hemodynamic activity and inter-area functional connectivity. During passive viewing, subjects' brain activity was synchronized in sensory projection and posterior temporal cortices. Simulation induced widespread increase of ISPS in the AON (premotor, posterior parietal, and superior temporal cortices), primary and secondary somatosensory cortices, and the dorsal attention circuits (frontal eye fields, intraparietal sulcus). Moreover, interconnectivity of these regions strengthened during simulation. We propose that sharing a third person's feelings synchronizes the observer's own brain mechanisms supporting sensations and motor planning, thereby likely promoting mutual understanding.Peer reviewe

Lifetime antipsychotic medication and cognitive performance in schizophrenia at age 43 years in a general population birth cohort

This naturalistic study analysed the association between cumulative lifetime antipsychotic dose and cognition in schizophrenia after an average of 16.5 years of illness. Sixty participants with schizophrenia and 191 controls from the Northern Finland Birth Cohort 1966 were assessed at age 43 years with a neurocognitive test battery. Cumulative lifetime antipsychotic dose-years were collected from medical records and interviews. The association between antipsychotic dose-years and a cognitive composite score based on principal component analysis was analysed using linear regression. Higher lifetime antipsychotic dose-years were significantly associated with poorer cognitive composite score, when adjusted for gender, onset age and lifetime hospital treatment days. The effects of typical and atypical antipsychotics did not differ. This is the first report of an association between cumulative lifetime antipsychotic dose and global cognition in midlife schizophrenia. Based on these data, higher lifetime antipsychotic dose-years may be associated with poorer cognitive performance at age 43 years. Potential biases related to the naturalistic design may partly explain the results; nonetheless, it is possible that large antipsychotic doses harm cognition in schizophrenia in the long-term.Peer reviewe

Dissociable Roles of Cerebral mu-Opioid and Type 2 Dopamine Receptors in Vicarious Pain: A Combined PET-fMRI Study

Neuroimaging studies have shown that seeing others in pain activates brain regions that are involved in first-hand pain, suggesting that shared neuromolecular pathways support processing of first-hand and vicarious pain. We tested whether the dopamine and opioid neurotransmitter systems involved in nociceptive processing also contribute to vicarious pain experience. We used in vivo positron emission tomography to quantify type 2 dopamine and mu-opioid receptor (D2R and MOR, respectively) availabilities in brains of 35 subjects. During functional magnetic resonance imaging, the subjects watched short movie clips depicting persons in painful and painless situations. Painful scenes activated pain-responsive brain regions including anterior insulae, thalamus and secondary somatosensory cortices, as well as posterior superior temporal sulci. MOR availability correlated negatively with the haemodynamic responses during painful scenes in anterior and posterior insulae, thalamus, secondary and primary somatosensory cortices, primary motor cortex, and superior temporal sulci. MOR availability correlated positively with orbitofrontal haemodynamic responses during painful scenes. D2R availability was not correlated with the haemodynamic responses in any brain region. These results suggest that the opioid system contributes to neural processing of vicarious pain, and that interindividual differences in opioidergic system could explain why some individuals react more strongly than others to seeing pain

Airway obstruction, serum vitamin D and mortality in a 33-year follow-up study

Background and objective: Chronic obstructive pulmonary disease and low vitamin D status predict mortality, but their combined effect on mortality remains inconclusive. We aimed to investigate a joint effect of airway obstruction and vitamin D status on mortality in a nationally representative cohort. Methods: We analysed data of 6676 Finnish adults participating between 1978 and 1980 in a national health examination survey, undergoing spirometry and having all necessary data collected. We followed them up in national registers through record linkage until 31 December 2011. We categorised the subjects with obstruction using the lower limit of normal (LLN) and the measured serum 25-hydroxyvitamin-D (s-25(OH)D) into tertiles. Results: Both obstruction and low s-25(OH) D independently predicted mortality in a multivariate model adjusted also for age, sex, smoking, education, leisure physical activity, body mass index, asthma and serum C-reactive protein. However, a statistically significant (p = 0.007) interaction emerged: the adjusted mortality HRs (95% CI's) for s-25(OH)D in tertiles among the subjects without and with obstruction were 1.00 (lowest), 0.96 (0.87-1.05) and 0.89 (0.81-0.98); and 1.00, 0.96 (0.71-1.31) and 0.57 (0.40-0.80), respectively. Conclusions: In conclusion, obstruction and low s-25(OH)D predict mortality independently of each other. Our findings suggest that low vitamin D status might be particularly detrimental among subjects with obstruction.Peer reviewe

A vertex detector for the International Linear Collider based on CMOS sensors

The physics programme at the International Linear Collider (ILC) calls for a vertex detector (VD) providing unprecedented flavour tagging performances, especially for c-quarks and τ leptons. This requirement makes a very granular, thin and multi-layer VD installed very close to the interaction region mandatory. Additional constraints, mainly on read-out speed and radiation tolerance, originate from the beam background, which governs the occupancy and the radiation level the detector should be able to cope with. CMOS sensors are being developed to fulfil these requirements. This report addresses the ILC requirements (highly related to beamstrahlung), the main advantages and features of CMOS sensors, the demonstrated performances and the specific aspects of a VD based on this technology. The status of the main R&D directions (radiation tolerance, thinning procedure and read-out speed) are also presented

Assessment of Epidermal Growth Factor Receptor (EGFR) expression in human meningioma

<p>Abstract</p> <p>Purpose</p> <p>This study explores whether meningioma expresses epidermal growth factor receptor (EGFR) and determines if there is a correlation between the WHO grade of this tumor and the degree of EGFR expression.</p> <p>Methods</p> <p>Following institutional review board approval, 113 meningioma specimens from 89 patients were chosen. Of these, 85 were used for final analysis. After a blinded review, immunohistochemical stains for EGFR were performed. Staining intensity (SI) was scored on a scale 0-3 (from no staining to strong staining). Staining percentage of immunoreactive cells (SP) was scored 1-5 (from the least to the maximum percent of the specimen staining). Immunohistochemical score (IHS) was calculated as the product of SI and SP.</p> <p>Results</p> <p>Eighty-five samples of meningioma were classified in accordance with World Health Organization (WHO) criteria: benign 57/85 (67%), atypical 23/85 (27%), and malignant 5/85 (6%). The majority of samples demonstrated a moderate SI for EGFR. IHS for EGFR demonstrated a significant association between SI and histopathologic subtype. Also, there was a correlation between the SP and histopathologic subtype (p = 0.029). A significant association was determined when the benign and the atypical samples were compared to the malignant with respect to the SP (p = 0.009). While there was a range of the IHS for the benign and the atypical histologic subtypes, malignant tumors exhibited the lowest score and were statistically different from the benign and the atypical specimens (p < 0.001).</p> <p>Conclusions</p> <p>To our knowledge, this represents the largest series of meningioma samples analyzed for EGFR expression reported in the literature. EGFR expression is greatest in benign meningiomas and may serve a potential target for therapeutic intervention with selective EGFR inhibitors.</p

Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal