The Haar measure plays a vital role in quantum information, but its study often requires a deep understanding of representation theory, posing a challenge for beginners. This tutorial aims to provide a basic introduction to Haar measure tools in quantum information, utilizing only basic knowledge of linear algebra and thus aiming to make this topic more accessible. The tutorial begins by introducing the Haar measure with a specific emphasis on characterizing the moment operator, an essential element for computing integrals over the Haar measure. It also covers properties of the symmetric subspace and introduces helpful tools like tensor network diagrammatic notation, which aid in visualizing and simplifying calculations. Next, the tutorial explores the concept of unitary designs, providing equivalent definitions, and subsequently explores approximate notions of unitary designs, shedding light on the relationships between these different notions. Practical examples of Haar measure calculations are illustrated, including the derivation of well-known formulas such as the twirling of a quantum channel. Lastly, the tutorial showcases the applications of Haar measure calculations in quantum machine learning and classical shadow tomography.
View lessConspiracy theories have become a prominent topic for sociological research. But although emotions such as paranoia and panic are—sometimes dismissively—referred to in classical accounts of conspiracy theories and different emotions have been empirically linked to conspiracy beliefs, a comprehensive theoretical account of the emotional underpinnings of conspiracy theories is still lacking. In this contribution, I aim to fill this gap by proposing a theoretical model that focuses on the transformation and collectivisation of emotions, facilitated by conspiracy theories. Drawing on existing research, I first identify three groups of emotions relevant to conspiracy theories: (1) anxiety and fear, (2) excitement, fascination and awe and (3) anger, ressentiment and hate. Many of these emotions are both considered to drive individuals towards conspiratorial beliefs and are found to be evoked by conspiracy theories, which raises questions regarding their causal relationship to conspiracy theories. To clarify this conceptual ambiguity, I propose a processual account, according to which conspiracy theories enable the transformation of individual emotions which are marked by powerlessness and thus are frequently suppressed into emotions that are less harmful to the self and can be expressed and acted upon. Crucially, the resulting emotions are experienced collectively and consequently can drive the formation of emotional collectives. Thus, the emotional mechanism does not only motivate individuals to subscribe to conspiracy beliefs but also allows them to reassert their collective political agency and sense of control. In this process, however, the original emotional concern may be lost, resulting in potentially misdirected political actions.
View lessThe [4+2] cycloaddition of 2-(2′-pyridyl)-4,6-diphenyl-λ3-phosphinine with the highly reactive dienophile hexafluoro-2-butyne has been studied and the first pyridyl-functionalized 1-phosphabarrelene was obtained and structurally characterized. Although monodentate CF3-1-phosphabarrelenes show only a poor coordination ability, the chelating nature of the novel P,N-hybrid ligand gives access to various transition-metal complexes. Upon irradiation with UV light, the pyridyl-functionalized 1-phosphabarrelene undergoes a rather selective di-π-methane rearrangement in the coordination sphere of the metal center, leading to the formation of a complex based on a hitherto unknown pyridyl-functionalized 5-phosphasemibullvalene derivative. DFT calculations provide first insights into the mechanism of this reaction.
View lessThere is a folkloric belief that a depth-Θ(m) quantum circuit is needed to estimate the trace of the product of m density matrices (i.e., a multivariate trace), a subroutine crucial to applications in condensed matter and quantum information science. We prove that this belief is overly conservative by constructing a constant quantum-depth circuit for the task, inspired by the method of Shor error correction. Furthermore, our circuit demands only local gates in a two dimensional circuit – we show how to implement it in a highly parallelized way on an architecture similar to that of Google's Sycamore processor. With these features, our algorithm brings the central task of multivariate trace estimation closer to the capabilities of near-term quantum processors. We instantiate the latter application with a theorem on estimating nonlinear functions of quantum states with "well-behaved" polynomial approximations.
View lessWe propose a unifying paradigm for analyzing and constructing topological quantum error correcting codes as dynamical circuits of geometrically local channels and measurements. To this end, we relate such circuits to discrete fixed-point path integrals in Euclidean spacetime, which describe the underlying topological order: If we fix a history of measurement outcomes, we obtain a fixed-point path integral carrying a pattern of topological defects. As an example, we show that the stabilizer toric code, subsystem toric code, and CSS Floquet code can be viewed as one and the same code on different spacetime lattices, and the honeycomb Floquet code is equivalent to the CSS Floquet code under a change of basis. We also use our formalism to derive two new error-correcting codes, namely a Floquet version of the 3+1-dimensional toric code using only 2-body measurements, as well as a dynamic code based on the double-semion string-net path integral.
View lessFluid–rock interactions play a key role in the formation, evolution and recycling of the Earth's crust. For fluids to infiltrate rocks and enable and sustain fluid-mediated mineral transformations, fluid pathways are required. In this study, we examined the potential mechanisms of formation of such pathways via detailed mineralogical, petrophysical and thermodynamic analysis of a dry, essentially ‘non-porous’ gabbro that was hydrated and transformed into an amphibolite under amphibolite-facies conditions. During a previous regional HP eclogite-facies metamorphism, the gabbro did not equilibrate and preserved almost entirely its igneous textures and magmatic minerals. Rock transformation during amphibolitization was triggered by fluid infiltration through a newly opened N–S striking fracture network. An equally spaced fracture network formed by mode I opening related to the formation of an E–W striking shear zone at the northern and southern borders of the gabbro body. The amphibolitization process allowed the fluid to pervasively infiltrate the rock from the fracture into the pristine gabbro. The essentially fully amphibolitized sample exhibits some unaffected gabbroic mineral relicts. Even though the amphibolitization process led to the formation of ~70 vol.% hydrous phases, it was accompanied by densification and related porosity formation. The modes and compositions of minerals within partly amphibolitized rocks indicate that besides the uptake of H2O, no significant mass exchanges were necessary for this transformation, at least on the thin section scale. Thermodynamic modelling and petrological data show that the transition from gabbro to amphibolite favours porosity formation. In the model, the reaction front proceeded as soon as the gabbro at the reactive interfaces of the affected minerals was sufficiently transformed. At this point, fluid was not consumed further but remained as a free fluid phase, which progressed through the newly formed pore space and advanced amphibolitization. Once the gabbro was almost entirely amphibolitized, its mineral content and mineral chemistry no longer changed, so the progress of amphibolitization progress was controlled by fluid availability. This case study shows that fluid–rock interaction leading to hydration of a rock can be efficiently maintained in almost non-permeable, dry and mafic crust and, therefore, strongly affects the petrophysical properties of the Earth's crust.
View lessIn the max–min allocation problem a set P of players are to be allocated disjoint subsets of a set R of indivisible resources, such that the minimum utility among all players is maximized. We study the restricted variant, also known as the Santa Claus problem, where each resource has an intrinsic positive value, and each player covets a subset of the resources.Bezáková and Dani (SIGecom Exch 5(3):11–18, 2005) showed that this problem is NP-hard to approximate within a factor less than 2, consequently a great deal of work has focused on approximate solutions. The principal approach for obtaining approximation algorithms has been via the Configuration LP (CLP) of Bansal and Sviridenko (Proceedings of the 38th ACMSymposium on Theory of Computing, 2006). Accordingly, there has been much interest in bounding the integrality gap of this CLP. The existing algorithms and integrality gap estimations are all based one way or another on the combinatorial augmenting tree argument of Haxell (Graphs Comb 11(3):245–248, 1995) for finding perfect matchings in certain hypergraphs. Our main innovation in this paper is to introduce the use of topological methods, to replace the combinatorial argument of Haxell (Graphs Comb 11(3):245–248, 1995) for the restricted max–min allocation problem. This approach yields substantial improvements in the integrality gap of the CLP. In particular we improve the previously best known bound of 3.808 to 3.534. We also study the (1, ε)-restricted version, in which resources can take only two values, and improve the integrality gap in most cases. Our approach applies a criterion of Aharoni and Haxell, and Meshulam, for the existence of independent transversals in graphs, which involves the connectedness of the independence complex. This is complemented by a graph process of Meshulam that decreases the connectedness of the independence complex in a controlled fashion and hence, tailored appropriately to the problem, can verify the criterion. In our applications we aim to establish the flexibility of the approach and hence argue for it to be a potential asset in other optimization problems involving hypergraph matchings.
View lessZeitpolitische Maßnahmen wie die Arbeitszeitverkürzung von Lohnarbeit stehen aktuell im Zentrum gesellschaftlicher und wissenschaftlicher Debatten. Feministische Perspektiven betrachten die Verkürzung der Lohnarbeit als Chance, Sorgearbeit gerechter zu verteilen und Sorgeverantwortliche zu entlasten. Ökologische Ansätze knüpfen daran die Hoffnung, Emissionen und Ressourcenverbrauch durch die Reduktion des Produktionssektors zu verringern. Beide Perspektiven bleiben jedoch in einem lohnarbeitszentrierten und quantitativ orientierten Verständnis von Zeit verhaftet, das den multiplen Rhythmen des Lebens und der Sorge nicht gerecht wird.
Dieser Beitrag entwickelt, ausgehend von queerfeministischen Zeittheorien und dem Konzept more-than-human-care, eine zeittheoretische Perspektive, die das Verständnis von (öko)feministischen Zeitpolitiken erweitert. Die Temporalitäten von more-than-human-care werden als multipel, spiralförmig und divergierend konzipiert. Der Artikel argumentiert, dass diese Temporalitäten zentrale Impulse für eine ökofeministische Transformation der Zeitpolitik liefern können, und entwickelt abschließend Prämissen für eine sorgezentrierte ökofeministische Zeitpolitik.
View lessThe ectodomain of the Omicron SARS-CoV-2 spike has an increased positive surface charge, favoring binding to the host cell surface, but may affect the stability of the ectodomain. Thermal stability studies identified two transitions associated with the flexibility of the receptor binding domain and the unfolding of the whole ectodomain, respectively. Despite destabilizing effects of some mutations, compensatory mutations maintain ECD stability and functional advantages thus supporting viral fitness.
View lessBackground
Receptor-activated SMADs trimerize with SMAD4 to regulate context-dependent target gene expression. However, the presence of a single SMAD1/5/8 binding motif in cis-regulatory elements alone does not trigger transcription in native contexts. We hypothesize that binding to composite motifs in which at least two SMAD binding sites are in close proximity would be enough to induce transcription as this scenario allows the simultaneous interaction of at least two SMAD proteins, thereby increasing specificity and affinity.
Results
Using more than 65 distinct firefly luciferase constructs, we delineated the minimal requirements for BMP-induced gene activation. We propose a model in which two SMAD-MH1 domains bind a SMAD-composite motif in a back-to-back fashion with a 5-bp distance between the SMAD-motifs on opposing DNA strands. However screening of SMAD1-bound regions across a variety of cell types highlights that these composite motifs are extremely uncommon, explaining below 1% of SMAD1 binding events.
Conclusions
Deviations from these minimal requirements prevent transcription and underline the need for co-transcription factors to achieve gene activation.
View lessThe stereoselective introduction of glycosidic bonds is one of the greatest challenges in carbohydrate chemistry. A key aspect of controlling glycan synthesis is the glycosylation reaction in which the glycosidic linkages are formed. The outcome is governed by a reactive sugar intermediate - the glycosyl cation. Glycosyl cations are highly unstable and short-lived, making them difficult to study using established analytical tools. However, mass-spectrometry-based techniques are perfectly suited to unravel the structure of glycosyl cations in the gas phase. The main approach involves isolating the reactive intermediate, free from external influences such as solvents and promoters. Isolation of the cations allows examining their structure by integrating orthogonal spectrometric and spectroscopic technologies. In this perspective, recent achievements in gas-phase research on glycosyl cations are highlighted. It provides an overview of the spectroscopic techniques used to probe the glycosyl cations and methods for interpreting their spectra. The connections between gas-phase data and mechanisms in solution synthesis are explored, given that glycosylation reactions are typically performed in solution.
View lessObjectives: Pseudarthrosis after mandibular reconstruction leads to chronic overload of the osteosynthesis and impedes dental rehabilitation. This study evaluates the impact of gap site on osseous union in mandible reconstruction using a new volumetric analysis method with repeated cone-beam computed tomography (CBCT).
Methods: The degree of bone regeneration was evaluated in 16 patients after mandible reconstruction with a fibula free flap and patient-specific reconstruction plates. Percentual bone volume and width changes in intersegmental gaps were retrospectively analyzed using a baseline CBCT in comparison to a follow-up CBCT. Patients’ characteristics, plate-related complications, and gap sites (anterior/posterior) were analyzed. Detailed assessments of both gap sites (buccal/lingual/superior/inferior) were additionally performed.
Results: Intersegmental gap width (p = 0.002) and site (p < 0.001) significantly influence bone volume change over two consecutive CBCTs. An initial larger gap width resulted in a lower bone volume change. In addition, anterior gaps showed significantly less bone volume changes. Initial gap width was larger at posterior segmental gaps (2.97 vs 1.65 mm, p = 0.017).
Conclusions: A methodology framework has been developed that allows to quantify pseuarthrosis in reconstructed mandibles using CBCT imaging. The study identifies the anterior segmental gap as a further risk factor for pseudarthrosis in reconstructions with CAD/CAM reconstruction plates. Future research should evaluate whether this outcome is related to the biomechanics induced at this site.
View lessObjective Specialized literature has identified a need for evidence-based, low-threshold, short-term, and intracultural psychological interventions that can be made available to migrants, including refugees, who suffer from psychological symptoms in host countries. The objective of the present study is to measure the efficacy of value-based counselling (VBC) as such an intervention.
Method We conducted a pragmatic, rater-blinded randomized controlled trial employing a pre-post control group design to assess the efficacy of VBC based on a study sample of 103 migrants, including refugees, who resided in Germany at the time. A set of instruments was used to evaluate primary outcome measures of depression, posttraumatic stress disorder (PTSD) symptoms, perceived stress, generalized anxiety, and somatic complaints.
Results Per protocol analysis included 42 participants in the VBC group, and 43 in the waiting list. Compared with participants in the waiting-list group, the VBC group, following an average of four counselling sessions, experienced a clinically meaningful reduction of depression (adjusted difference 7.06, 95% CI [4.86, 9.26], effect size 0.68, p < .001), PTSD (adjusted difference 17.15, 95% CI [10.49, 23.81], effect size 0.76, p < .001), perceived stress (adjusted difference 9.25, 95% CI [6.23, 12.27], effect size 0.75, p < .001), anxiety (adjusted difference 5.34, 95% CI [3.47, 7.20], effect size 0.70, p < .001), and somatic complaints (adjusted difference 5.52, 95% CI [3.30, 7.74], effect size 0.72, p < .001). The positive outcomes were maintained at 3-month follow-up. Utilization of mental health services was significantly reduced at the 3-month follow-up conducted with participants of the VBC group.
Conclusions VBC, a culturally sensitive and strength-based mental health service, is an effective short-term intervention which meets the specific mental health needs of migrants, including refugees.
View lessObjective This systematic review evaluated the effectiveness of soft tissue augmentation procedures for complete coverage and mean coverage of buccal soft tissue dehiscence (BSTD) in patients with implant-supported restorations.
Methods Three databases were surveyed for randomized (RCTs), non-randomized controlled clinical trials (CCTs), cohort studies, case–control studies, and case series with a minimum of five patients per control or test group. Studies dealing with soft tissue augmentation procedures to cover BSTD—occurring during implant function and not due to the result of peri-implantitis—were included. Risk of bias was evaluated with RoB 2 or the National Institutes of Health's Quality Assessment. Whenever possible, exploratory meta-analyses were performed to evaluate weighted mean effects (WME) for the different outcomes. The primary outcomes were the percentage of complete coverage and mean coverage of BSTD.
Results Seven articles were included. Only one study was a RCT, with a high risk of bias. Meta-analyses showed that after 1 year (2 studies, n = 36 patients; WME = 70; 95% confidence interval [CI] = 50; 90; p = .23) as well as after 5 years (3 studies, n = 54 patients; WME = 70; 95%; CI = 60; 80; p = .44), complete coverage of BSTD could be achieved in 70% of the cases.
Conclusion Based on limited evidence, it can be concluded that BSTD can be substantially reduced with the use of soft tissue augmentation procedures. Further research with comparative trials using larger samples and longer follow-up periods is needed to study the stability of soft tissues in the long term.
View lessKnown hereditary human diseases featuring impaired copper trafficking across cellular membranes involve ATP7A (Menkes disease, occipital horn disease, X-linked spinal muscular atrophy type 3) and ATP7B (Wilson disease). Herein, we report a newborn infant of consanguineous parents with a homozygous pathogenic variant in a highly conserved sequence of SLC31A1, coding for the copper influx transporter 1, CTR1. This missense variant, c.236T > C, was detected by whole exome sequencing. The infant was born with pulmonary hypoplasia and suffered from severe respiratory distress immediately after birth, necessitating aggressive mechanical ventilation. At 2 weeks of age, multifocal brain hemorrhages were diagnosed by cerebral ultrasound and magnetic resonance imaging, together with increased tortuosity of cerebral arteries. Ensuing seizures were only partly controlled by antiepileptic drugs, and the infant became progressively comatose. Laboratory investigations revealed very low serum concentrations of copper and ceruloplasmin. No hair shaft abnormalities were detected by dermatoscopy or light microscopic analyses of embedded hair shafts obtained at 4 weeks of life. The infant died after redirection of care and elective cessation of invasive mechanical ventilation at 1 month of age. This case adds SLC31A1 to the genes implicated in severe hereditary disorders of copper transport in humans.
View lessBackground Patients with atopic dermatitis (AD) frequently use acupuncture (ACU) and osteopathic medicine (OM), although their therapeutic benefits are unclear.
Aim To investigate the effectiveness of ACU and OM in patients with AD.
Methods In a three‐armed, single‐centre, randomized controlled open explorative clinical trial, adult patients with AD received ACU, OM or no study intervention (control group; CG) plus routine care. Outcomes included disease severity (SCORing Atopic Dermatitis; SCORAD), itching intensity (visual analogue scale; VAS), frequency of topical corticosteroid (TCS) use over 7 days and cost‐effectiveness. Endpoints were analysed by analysis of covariance adjusted for the respective baseline value and TCS use.
Results Overall, 121 patients (92 women, 29 men) with a mean ± SD age of 31.4 ± 10.5 years were randomized. After 12 weeks, the adjusted means (95% CI) for ACU, OM and control were, respectively, 22.3 (18.3–26.3), 26.4 (22.6–30.2) and 23.7 (19.9–27.5) for SCORAD (P = 0.32); 27.9 (19.5–36.4), 35.0 (26.9–43.0) and 42.3 (34.7–50.0) for VAS itching (P < 0.05); and 2.3 (0.8–3.9), 1.9 (0.4–3.5) and 4.3 (2.6–6.0), for TCS use (P = 0.10). ACU and OM were not cost‐effective compared with the CG.
Conclusion Although no differences in disease severity were found, our findings indicate that ACU might reduce itching in patients with AD. Furthermore, ACU and OM showed a trend towards reducing TCS use.
View lessThe impact on health-related quality of life (HRQL) plays a key role for patients suffering from allergies and anaphylaxis. In this narrative review we review the HRQL in allergic patients suffering from food and venom allergy, both being the most frequent elicitors of severe allergic, potential life-threatening reactions and provide an overview on the current knowledge and identified gaps.
The data show that for food and venom allergy standardized assessment tools to measure HRQL are available and have been successfully applied. Our analysis shows that multiple factors can modulate HRQL in these patient groups. These include sociodemographic data like patients' age and sex, fear of accidental reactions but also external factors like the social environment and the appreciation of the seriousness of the condition by others. External factors may have a significant impact on HRQL and should be considered in patient-related outcome assessments to avoid biased measurements possibly affecting the results. The assessment of the quality of life in the context of specific immunotherapy should consider lifestyle factors and ideally, the individual change in HRQL should be measured.
Although there are many data indicating a negative impact on HRQL in food allergic children and their caregivers, limited data are existing from adults with food allergy and venom allergic patients from all age groups. Also, the use of standardized questionnaires should be extended to allow for a better comparability of results between studies. Therefore, translation to additional languages is necessary.
Taken together, the eliciting allergen, the severity of the allergic disease but moreover multiple external factors impact the outcome in HRQL and should be considered in HRQL assessment.
View lessIn patients with hereditary angioedema (HAE), bradykinin causes swelling episodes by activating bradykinin B-2 receptors. Icatibant, a selective bradykinin B-2 receptor antagonist, is approved for on-demand treatment of HAE attacks. The Icatibant Outcome Survey (IOS; NCT01034969) is an ongoing observational registry initiated in 2009 to monitor the effectiveness/safety of icatibant in routine clinical practice. As of March 2019, 549 patients with HAE type 1 or 2 from the IOS registry had been treated of 5995 total attacks. This article reviews data published from IOS over time which have demonstrated that the effectiveness of icatibant in a real-world setting is comparable to efficacy in clinical trials; one dose is effective for the majority of attacks; early treatment (facilitated by self-administration) leads to faster resolution and shorter attack duration; effectiveness/safety of icatibant has been shown across a broad range of patient subgroups, including children/adolescents and patients with HAE with normal C1 inhibitor levels; and tolerability has been demonstrated in patients aged >= 65 years. Additionally, this review highlights how IOS data have provided valuable insights into patients' diagnostic journeys and treatment behaviours across individual countries. Such findings have helped to inform clinical strategies and guidelines to optimise HAE management and limit disease burden.
View lessBackground Food allergy is a growing health concern with a prevalence of 2%–3% in the adult population in Europe. Non-immune-mediated food hypersensitivities, which include reactions after ingestion of food additives, affect 1% of adults and may resemble IgE-induced allergic reactions without identifiable immunologic sensitization. A double-blind placebo-controlled food challenge (DBPCFC) is the gold standard for the diagnosis of any food hypersensitivity.
Objective We analysed a large group of adult patients with suspected food hypersensitivity, who had undergone DBPCFC, to better understand IgE-mediated food allergy and non-immune-dependent food hypersensitivity to food additives in adults regarding elicitors, symptoms and positivity rates of oral challenges.
Methods Data from 541 patients with suspected food hypersensitivity were analysed, who underwent an oral food challenge between 2010 and 2019.
Results IgE-dependent food allergy was confirmed in 114 of 329 adult patients (34.6%). The confirmation rate was lower in the group of patients with suspected non-immune-mediated reactions to food additives (65 of 286, 22.7%). Urticaria and angioedema appeared more frequently in patients with IgE-mediated food allergies. By contrast, flush and diarrhoea were the most frequent symptoms after a challenge in the group with the non-immune-mediated reactions to food additives. Wheat and celery were the most frequently identified food allergens in adults, whereas colourings and preservatives were the most frequent elicitors of non-immune-mediated food hypersensitivity.
Conclusion The importance of oral food challenges for the diagnosis of food hypersensitivity is confirmed. IgE-dependent food allergy is more frequently proven, reaching a positivity rate of one-third and only about 20% for non-immune-mediated hypersensitivity. Future studies should elaborate on the mechanisms of non-immune-mediated food hypersensitivity and the clinical impact of cofactors in this setting.
View lessBackground Only a small number of apps addressing allergic rhinitis (AR) patients have been evaluated. This makes their selection difficult. We aimed to introduce a new approach to market research for AR apps, based on the automatic screening of Apple App and Google Play stores.
Methods A JavaScript programme was devised for automatic app screening, and applied in a market assessment of AR self-management apps. We searched the Google Play and Apple App stores of three countries (USA, UK and Australia) with the following search terms: "hay fever", "hayfever", "asthma", "rhinitis", "allergic rhinitis". Apps were eligible if symptoms were evaluated. Results obtained with the automatic programme were compared to those of a blinded manual search. As an example, we used the search to assess apps that can be used to design a combined medication score for AR.
Results The automatic search programme identified 39 potentially eligible apps out of a total of 1593 retrieved apps. Each of the 39 apps was individually checked, with 20 being classified as relevant. The manual search identified 19 relevant apps (out of 6750 screened apps). Combining both methods, a total of 21 relevant apps were identified, pointing to a sensitivity of 95% and a specificity of 99% for the automatic method. Among these 21 apps, only two could be used for the combined symptom-medication score for AR.
Conclusions The programmed algorithm presented herein is able to continuously retrieve all relevant AR apps in the Apple App and Google Play stores, with high sensitivity and specificity. This approach has the potential to unveil the gaps and unmet needs of the apps developed so far.
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