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1.
Neuroimage ; 184: 687-696, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30287300

RESUMO

Being in control of one's emotions is not only desirable in many everyday situations but is also a great challenge in a variety of mental disorders. Successful intentional emotion regulation is related to down-regulation of amygdala activity. Training mental interventions supported by neurofeedback of one's own amygdala activity using real-time (rt-)fMRI might be beneficial for mental health and well-being. Rt-fMRI guided amygdala-downregulation using cognitive interventions such as a "reality check", however, have not been well-investigated. Fifteen healthy subjects underwent four rt-fMRI sessions with neurofeedback of their own amygdala activity while applying a reality check as an emotion regulation strategy in order to down-regulate their amygdala signal during a stimulation with emotional pictures. The Control group comprised of eleven subjects also trained emotion regulation but without obtaining feedback. We hypothesized more prominent down-regulation of amygdala activity at the end of the training in the Feedback group. We investigated effects over time and between groups and further task specific connectivity of the amygdala by using psychophysiological interaction analyses. Four weekly amygdala-based feedback sessions resulted in significantly decreased amygdala activity (p = 0.003, d = 0.93), also compared to the Control group (p = 0.014, d = 1.12). Task specific connectivity of the amygdala with the anterior cingulate cortex, hippocampus and distinct prefrontal areas was increased in the Feedback group. Training of emotion regulation supported by rt-fMRI neurofeedback resulted in a prominent amygdala down-regulation compared to training without feedback. The finding implicates successful emotion regulation, compliant with emotion control models, through an easily applicable reality check strategy. Rt-fMRI neurofeedback may support emotion regulation learning and bears clinical potential for psychotherapy.


Assuntos
Tonsila do Cerebelo/fisiologia , Emoções/fisiologia , Neurorretroalimentação/métodos , Autocontrole/psicologia , Adulto , Mapeamento Encefálico/métodos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética , Masculino , Adulto Jovem
2.
Phys Rev Lett ; 121(18): 180501, 2018 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-30444422

RESUMO

Constructing a large-scale ion trap quantum processor will require entangling gate operations that are robust in the presence of noise and experimental imperfection. We experimentally demonstrate how a new type of Mølmer-Sørensen gate protects against infidelity caused by heating of the motional mode used during the gate. Furthermore, we show how the same technique simultaneously provides significant protection against slow fluctuations and mis-sets in the secular frequency. Since this parameter sensitivity is worsened in cases where the ions are not ground-state cooled, our method provides a path towards relaxing ion cooling requirements in practical realizations of quantum computing and simulation.

3.
Mol Psychiatry ; 22(8): 1164-1171, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-27922605

RESUMO

Social anxiety disorder (SAD) is characterized by fears of social and performance situations. Cognitive behavioral group therapy (CBGT) has in general positive effects on symptoms, distress and avoidance in SAD. Prior studies found increased cortical volumes and decreased fractional anisotropy (FA) in SAD compared with healthy controls (HCs). Thirty-three participants diagnosed with SAD attended in a 10-week CBGT and were scanned before and after therapy. We applied three neuroimaging methods-surface-based morphometry, diffusion tensor imaging and network-based statistics-each with specific longitudinal processing protocols, to investigate CBGT-induced structural brain alterations of the gray and white matter (WM). Surface-based morphometry revealed a significant cortical volume reduction (pre- to post-treatment) in the left inferior parietal cortex, as well as a positive partial correlation between treatment success (indexed by reductions in Liebowitz Social Anxiety Scale) and reductions in cortical volume in bilateral dorsomedial prefrontal cortex. Diffusion tensor imaging analysis revealed a significant increase in FA in bilateral uncinate fasciculus and right inferior longitudinal fasciculus. Network-based statistics revealed a significant increase of structural connectivity in a frontolimbic network. No partial correlations with treatment success have been found in WM analyses. For, we believe, the first time, we present a distinctive pattern of longitudinal structural brain changes after CBGT measured with three established magnetic resonance imaging analyzing techniques. Our findings are in line with previous cross-sectional, unimodal SAD studies and extent them by highlighting anatomical brain alterations that point toward the level of HCs in parallel with a reduction in SAD symptomatology.


Assuntos
Encéfalo/patologia , Fobia Social/fisiopatologia , Fobia Social/terapia , Adulto , Transtornos de Ansiedade/patologia , Encéfalo/fisiologia , Mapeamento Encefálico , Terapia Cognitivo-Comportamental/métodos , Estudos Transversais , Imagem de Tensor de Difusão , Feminino , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética/métodos , Masculino , Rede Nervosa/patologia , Neuroimagem/métodos , Lobo Parietal/patologia , Fobia Social/diagnóstico por imagem , Córtex Pré-Frontal/patologia , Psicoterapia de Grupo/métodos , Suíça
4.
Phys Rev Lett ; 117(22): 220501, 2016 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-27925715

RESUMO

Trapped ions are a promising tool for building a large-scale quantum computer. However, the number of required radiation fields for the realization of quantum gates in any proposed ion-based architecture scales with the number of ions within the quantum computer, posing a major obstacle when imagining a device with millions of ions. Here, we present a fundamentally different approach for trapped-ion quantum computing where this detrimental scaling vanishes. The method is based on individually controlled voltages applied to each logic gate location to facilitate the actual gate operation analogous to a traditional transistor architecture within a classical computer processor. To demonstrate the key principle of this approach we implement a versatile quantum gate method based on long-wavelength radiation and use this method to generate a maximally entangled state of two quantum engineered clock qubits with fidelity 0.985(12). This quantum gate also constitutes a simple-to-implement tool for quantum metrology, sensing, and simulation.

5.
Psychol Med ; 46(7): 1427-36, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26804333

RESUMO

BACKGROUND: Obsessive compulsive disorder (OCD) and social anxiety disorder (SAD) are characterized by biased perception and processing of potentially threatening stimuli. A hyper-reactivity of the fear-circuit [e.g. amygdala, anterior cingulate (ACC)] has been consistently reported using functional magnetic resonance imaging (fMRI) in SAD in comparison with healthy controls (HCs). Studies investigating the processing of specific emotional stimuli in OCD reported mainly orbitofrontal-striatal abnormalities. The goal of this study was to examine similar/common and differential neurobiological responses in OCD and SAD using unspecific emotional stimuli. METHOD: Fifty-four subjects participated: two groups (each n = 18) of outpatients with a current diagnosis of OCD or SAD, and 18 HCs. All subjects underwent fMRI while anticipating and perceiving unspecific visual stimuli with prior announced emotional valence (e.g. positive). RESULTS: Compared to HCs, the combined patient group showed increased activation in amygdala, caudate and prefrontal/orbitofrontal cortex while anticipating unspecific emotional stimuli. Caudate was more active in the combined patient group during perception. A comparison between the OCD and the SAD samples revealed increased amygdala and decreased rostral ACC activation in OCD patients during perception, but no differences in the anticipation phase. CONCLUSIONS: Overall, we could identify common fronto-subcortical hyper-reactivity in OCD and SAD while anticipating and perceiving unspecific emotional stimuli. While differential neurobiological responses between OCD and SAD when processing specific stimuli are evident from the literature, differences were less pronounced using unspecific stimuli. This could indicate a disturbance of emotion regulation common to both OCD and SAD.


Assuntos
Tonsila do Cerebelo/fisiopatologia , Núcleo Caudado/fisiopatologia , Emoções/fisiologia , Giro do Cíngulo/fisiopatologia , Transtorno Obsessivo-Compulsivo/fisiopatologia , Fobia Social/fisiopatologia , Adulto , Antecipação Psicológica/fisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Percepção Visual/fisiologia , Adulto Jovem
6.
Phys Rev Lett ; 115(1): 013002, 2015 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-26182094

RESUMO

We demonstrate ground-state cooling of a trapped ion using radio-frequency (rf) radiation. This is a powerful tool for the implementation of quantum operations, where rf or microwave radiation instead of lasers is used for motional quantum state engineering. We measure a mean phonon number of n[over ¯]=0.13(4) after sideband cooling, corresponding to a ground-state occupation probability of 88(7)%. After preparing in the vibrational ground state, we demonstrate motional state engineering by driving Rabi oscillations between the |n=0⟩ and |n=1⟩ Fock states. We also use the ability to ground-state cool to accurately measure the motional heating rate and report a reduction by almost 2 orders of magnitude compared with our previously measured result, which we attribute to carefully eliminating sources of electrical noise in the system.

7.
Phys Rev Lett ; 111(14): 140501, 2013 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-24138229

RESUMO

Many schemes for implementing quantum information processing require that the atomic states used have a nonzero magnetic moment; however, such magnetically sensitive states of an atom are vulnerable to decoherence due to fluctuating magnetic fields. Dressing an atom with external fields is a powerful method of reducing such decoherence [N. Timoney et al., Nature (London) 476, 185 (2011)]. We introduce an experimentally simpler method of manipulating such a dressed-state qubit, which allows the implementation of general rotations of the qubit, and demonstrate this method using a trapped ytterbium ion.

8.
Nat Commun ; 14(1): 531, 2023 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-36754957

RESUMO

System scalability is fundamental for large-scale quantum computers (QCs) and is being pursued over a variety of hardware platforms. For QCs based on trapped ions, architectures such as the quantum charge-coupled device (QCCD) are used to scale the number of qubits on a single device. However, the number of ions that can be hosted on a single quantum computing module is limited by the size of the chip being used. Therefore, a modular approach is of critical importance and requires quantum connections between individual modules. Here, we present the demonstration of a quantum matter-link in which ion qubits are transferred between adjacent QC modules. Ion transport between adjacent modules is realised at a rate of 2424 s-1 and with an infidelity associated with ion loss during transport below 7 × 10-8. Furthermore, we show that the link does not measurably impact the phase coherence of the qubit. The quantum matter-link constitutes a practical mechanism for the interconnection of QCCD devices. Our work will facilitate the implementation of modular QCs capable of fault-tolerant utility-scale quantum computation.

9.
J Proteomics ; 285: 104941, 2023 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-37285906

RESUMO

There has been little information about the proteome of bovine faeces or about the contribution to the faecal proteome of proteins from the host, the feed or the intestinal microbiome. Here, the bovine faecal proteome and the origin of its component proteins was assessed, while also determining the effect of treating barley, the major carbohydrate in the feed, with either ammonia (ATB) or sodium propionate (PTB) preservative. Healthy continental crossbreed steers were allocated to two groups and fed on either of the barley-based diets. Five faecal samples from each group were collected on Day 81 of the trial and analysed by quantitative proteomics using nLC-ESI-MS/MS after tandem mass tag labelling. In total, 281 bovine proteins, 199 barley proteins, 176 bacterial proteins and 190 archaeal proteins were identified in the faeces. Mucosal pentraxin, albumin and digestive enzymes were among bovine proteins identified. Serpin Z4 a protease inhibitor was the most abundant barley protein identified which is also found in barley-based beer, while numerous microbial proteins were identified, many originating bacteria from Clostridium, while Methanobrevibacter was the dominant archaeal genus. Thirty-nine proteins were differentially abundant between groups, the majority being more abundant in the PTB group compared to the ATB group. SIGNIFICANCE: Proteomic examination of faeces is becoming a valuable means to assess the health of the gastro-intestinal tract in several species, but knowledge on the proteins present in bovine faeces is limited. This investigation aimed to characterise the proteome of bovine faecal extracts in order to evaluate the potential for investigations of the proteome as a means to assess the health, disease and welfare of cattle in the future. The investigation was able to identify proteins in bovine faeces that had been (i) produced by the individual cattle, (ii) present in the barley-based feed eaten by the cattle or (iii) produced by bacteria and other microbes in the rumen or intestines. Bovine proteins identified included mucosal pentraxin, serum albumin and a variety of digestive enzymes. Barley proteins found in the faeces included serpin Z4, a protease inhibitor that is also found in beer having survived the brewing process. Bacterial and archaeal proteins in the faecal extracts were related to several pathways related to the metabolism of carbohydrates. The recognition of the range of proteins that can be identified in bovine faeces raises the possibility that non-invasive sample collection of this material could provide a novel diagnostic approach to cattle health and welfare.


Assuntos
Proteínas Arqueais , Hordeum , Serpinas , Bovinos , Animais , Serpinas/análise , Proteoma/análise , Cerveja/análise , Proteômica , Espectrometria de Massas em Tandem , Dieta/veterinária , Fezes/microbiologia , Bactérias , Extratos Vegetais , Ração Animal/análise
10.
Nat Commun ; 5: 3637, 2014 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-24704758

RESUMO

Microfabricated ion traps are a major advancement towards scalable quantum computing with trapped ions. The development of more versatile ion-trap designs, in which tailored arrays of ions are positioned in two dimensions above a microfabricated surface, will lead to applications in fields as varied as quantum simulation, metrology and atom-ion interactions. Current surface ion traps often have low trap depths and high heating rates, because of the size of the voltages that can be applied to them, limiting the fidelity of quantum gates. Here we report on a fabrication process that allows for the application of very high voltages to microfabricated devices in general and use this advance to fabricate a two-dimensional ion-trap lattice on a microchip. Our microfabricated architecture allows for reliable trapping of two-dimensional ion lattices, long ion lifetimes, rudimentary shuttling between lattice sites and the ability to deterministically introduce defects into the ion lattice.

11.
Praxis (Bern 1994) ; 101(8): 523-30, 2012 Apr 11.
Artigo em Alemão | MEDLINE | ID: mdl-22492073

RESUMO

Anxiety disorders are common disorders associated with marked impairment and reduced quality of life. In the general practitioner's office as well as in the specialist's consultation, patients with anxiety disorders frequently present primarily somatic complaints. Many patients run through numerous checkups prior to be referred to psychiatric treatment. Some basic aspects can help to earlier identify patients suffering from anxiety disorders and to initiate sufficient therapy. With evidence-based treatment with cognitive-behavioral therapy and adequate psychopharmacotherapy, many patients can achieve complete remission of symptoms. Initial treatment can comprise specific psycho-education as well as first-line psychopharmacological treatment with e.g. SSRI.


Assuntos
Transtornos de Ansiedade/diagnóstico , Algoritmos , Ansiolíticos/efeitos adversos , Ansiolíticos/uso terapêutico , Transtornos de Ansiedade/classificação , Transtornos de Ansiedade/psicologia , Transtornos de Ansiedade/terapia , Terapia Cognitivo-Comportamental , Diagnóstico Diferencial , Medicina Baseada em Evidências , Humanos , Classificação Internacional de Doenças , Encaminhamento e Consulta , Suíça
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