Abstract We address quantum characterization of anisotropic spin chains in the presence of anti-symmetric exchange, and investigate whether the Hamiltonian parameters of the chain may be estimated ...with precision approaching the ultimate limit imposed by quantum mechanics. At variance with previous approaches, we focus on the information that may be extracted by measuring only two neighboring spins rather than a global observable on the entire chain. We evaluate the Fisher information (FI) of a two-spin magnetization measure, and the corresponding quantum Fisher information (QFI), for all the relevant parameters, i.e. the spin coupling, the anisotropy, and the Dzyaloshinskii–Moriya (DM) parameter. Our results show that the reduced system made of two neighboring spins may be indeed exploited as a probe to characterize global properties of the entire system. In particular, we find that the ratio between the FI and the QFI is close to unit for a large range of the coupling values. The DM coupling is beneficial for coupling estimation, since it leads to the presence of additional bumps and peaks in the FI and QFI, which are not present in a model that neglects exchange interaction and may be exploited to increase the robustness of the overall estimation procedure. Finally, we address the multiparameter estimation problem, and show that the model is compatible but sloppy, i.e. both the Uhlmann curvature and the determinant of the QFI matrix vanish. Physically, this means that the state of the system actually depends only on a reduced numbers of combinations of parameters, and not on all of them separately.
Patients with long-standing ulcerative colitis and Crohn's disease have an increased risk of developing colorectal cancer and patients with small intestinal Crohn's disease are at increased risk of ...small bowel adenocarcinoma. Colorectal cancer appearing on the ground of inflammatory bowel disease is the result of a process which is believed to begin from no dysplasia progressing to indefinite dysplasia, low-grade dysplasia, high-grade dysplasia and finally to invasive adenocarcinoma, although colorectal cancer can arise without proceeding through each of these steps. Ulcerative colitis patients with total proctocolectomy and ileal pouch anal-anastomosis have a rather low risk of dysplasia in the ileal pouch, although the anal transition zone should be monitored periodically, especially if chronic pouchitis is present with associated severe villous atrophy. Concerning the risk factors predisposing to colorectal cancer in the setting of ulcerative colitis or Crohn's disease, it seems that the risk increases with longer duration and greater anatomic extent of colitis, the degree of inflammation, and the presence of primary sclerosing cholangitis and family history of colorectal cancer. Concerning the mechanisms of carcinogenesis, it is now well established that the molecular alterations responsible for sporadic colorectal cancer, namely chromosomal instability, microsatellite instability and hypermethylation, also play a role in colitis-associated colon carcinogenesis. Chemoprevention strategies include the administration of agents such as aminosalicylates, ursodeoxycholic acid, and possibly folic acid and statins, the exact role of which remains to be further elucitated.
Control of spindle orientation is a fundamental process for embryonic development, morphogenesis and tissue homeostasis, while defects are associated with tumorigenesis and other diseases. Force ...sensing is one of the mechanisms through which division orientation is determined. Here we show that integrin β1 plays a critical role in this process, becoming activated at the lateral regions of the cell cortex in a ligand-independent manner. This activation is force dependent and polar, correlating with the spindle capture sites. Inhibition of integrin β1 activation on the cortex and disruption of its asymmetric distribution leads to spindle misorientation, even when cell adhesion is β1 independent. Examining downstream targets reveals that a cortical mechanosensory complex forms on active β1, and regulates spindle orientation irrespective of cell context. We propose that ligand-independent integrin β1 activation is a conserved mechanism that allows cell responses to external stimuli.
Canonical correlation analysis (CCA) is a classic statistical method for discovering latent co-variation that underpins two or more observed random vectors. Several extensions and variations of CCA ...have been proposed that have strengthened our capabilities in terms of revealing common random factors from multiview datasets. In this work, we first revisit the most recent deterministic extensions of deep CCA and highlight the strengths and limitations of these state-of-the-art methods. Some methods allow trivial solutions, while others can miss weak common factors. Others overload the problem by also seeking to reveal what is not common among the views - i.e., the private components that are needed to fully reconstruct each view. The latter tends to overload the problem and its computational and sample complexities. Aiming to improve upon these limitations, we design a novel and efficient formulation that alleviates some of the current restrictions. The main idea is to model the private components as conditionally independent given the common ones, which enables the proposed compact formulation. In addition, we also provide a sufficient condition for identifying the common random factors. Judicious experiments with synthetic and real datasets showcase the validity of our claims and the effectiveness of the proposed approach.
Most infectious agents use mucosal tissues as entry portals, thus, mucosae are frequently defined as a first line of defense against pathogens. Mucosal protection generally operates through ...antibody-mediated and cytotoxic T-cell responses which can be triggered by mucosal vaccines. Sublingual vaccination provides many advantages such as systemic and mucosal responses (both locally and at remote mucosal sites), besides being a needle-free administration route with high patient compliance and limited adverse effects. Buccal mucosa complexity nonetheless represents a challenge for vaccine administration, hence, many efforts were recently deployed to improve vaccine components, mucoadhesion and/or penetration. Several innovative approaches indeed confirmed that a robust and protective immunity can be achieved by sublingual vaccines. This review will then specify the most recent delivery systems and improvements developed to increase sublingual vaccines efficiency. We will focus our description on the immune mechanisms involved and the requirements for optimal sublingual immunization and mucosal protection.
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•Sublingual vaccination induces broad systemic and mucosal immunity.•Sublingually-induced immunity disseminates in both the respiratory and genital tract.•Mucosal vaccination allows needle-free and patient compliant administration.•Innovative sublingual delivery systems avoid dilution of vaccine formulations.•A controlled release of the vaccine through mucosa is essential for vaccine efficacy.
We address metrological protocols for the estimation of the intensity and the orientation of a magnetic field, and show that quantum-enhanced precision may be achieved by probing the field with an ...arbitrary spin at thermal equilibrium. A general expression is derived for the ultimate achievable precision, as given by the quantum Fisher information. The optimal observable is shown to correspond to the spin projection along a temperature-dependent direction, and allows a maximally precise parameter estimation also through ensemble measurements. Finally, we prove the robustness of our scheme against deviations of the measured spin projection from optimality.
Mapping the strong interaction between Rydberg atoms onto single photons via electromagnetically induced transparency enables manipulation of light at the single-photon level and few-photon devices ...such as all-optical switches and transistors operated by individual photons. Here we demonstrate experimentally that Stark-tuned Förster resonances can substantially increase this effective interaction between individual photons. This technique boosts the gain of a single-photon transistor to over 100, enhances the non-destructive detection of single Rydberg atoms to a fidelity beyond 0.8, and enables high-precision spectroscopy on Rydberg pair states. On top, we achieve a gain larger than 2 with gate photon read-out after the transistor operation. Theory models for Rydberg polariton propagation on Förster resonance and for the projection of the stored spin-wave yield excellent agreement to our data and successfully identify the main decoherence mechanism of the Rydberg transistor, paving the way towards photonic quantum gates.
•The monitored performance of the first passive house designed and constructed in Cyprus was investigated.•Overheating problems, monitored in all zones during the summer period.•Potential for ...improving thermal comfort conditions with night ventilation.•Effect of low-emissivity thermal paint on the external walls and roof was rather negligible.•Annual assessment proved that the performance of the building was within the passive house standard limits.
The principle of Passive Houses is an important milestone in the evolutionary development towards environmental friendly and energy efficient buildings. Τhe concept as such was developed in central Europe tackling primarily the issue of heating. However, as the goal of sustainability has become a common one throughout Europe and beyond, it is now established that the energy performance of Passive Houses has to satisfy thermal comfort under diverse climatic conditions, in order to enable its adequate global applicability. This study presents the monitored performance of the first Passive House designed and constructed in Cyprus, a south-eastern Mediterranean European country with subtropical climatic conditions. This study aims to provide useful insights to improve the performance of Passive Houses in subtropical climates. The “as built” performance of the investigated building is compared to its asset design, revealing design gaps and possibilities for improvement. Different zones of the building were selected for investigation and the percentage of overheating in the examined zones was specified. The thermal performance of the examined building was also numerically investigated, by means of dynamic simulation in order to consider improvement options. The simulation model was validated for a cooling design day. The performance of a single zone was further investigated using CFD simulation for a specific summer day and the effect of potential measures for the improvement of its thermal performance was evaluated. An average reduction of 1.4°C of the indoor air temperature was achieved by applying an optimized strategy for night ventilation, while the increase of the cooling capacity of the HVAC was found to significantly improve the thermal performance of the zone. The effect of external thermal coating application was also examined.
The increasing integration of renewable energy sources into the electricity sector for decarbonization purposes necessitates effective energy storage facilities, which can separate energy supply and ...demand. Battery Energy Storage Systems (BESS) provide a practical solution to enhance the security, flexibility, and reliability of electricity supply, and thus, will be key players in future energy markets. Directive 2019/944, which focuses on common rules for the internal market of electricity, provides a regulatory framework for the deployment of energy storage facilities. However, several gaps and challenges remain regarding the implementation of the directive, particularly in insular energy systems with immature storage infrastructures such as Cyprus, an EU Member State. This study examines these challenges and gaps by investigating the case study of Cyprus while also presenting the handling of energy storage in other European countries such as Germany and Poland. The primary aim of this study is to identify gaps in the legislation regarding energy storage and potential bottlenecks or monopolistic approaches that could hinder the widespread deployment of BESS under the liberalization of the energy market. In light of several BESS technologies available in the market, the study focuses on lithium-based technologies, which account for the largest share of the BESS market and are projected to grow at the highest compound annual growth rate by 2030. Therefore, the authors concentrate on Lithium BESS. The study highlights the crucial role of storage facilities in transforming the power generation sector by shifting toward renewable sources of energy. As such, the study emphasizes the importance of effective regulatory frameworks in enabling the deployment of BESS, particularly in insular energy systems. Overall, this study sheds light on the gaps and challenges facing the deployment of BESS, providing valuable insights for policymakers and stakeholders to design effective regulatory frameworks to facilitate the widespread adoption of BESS.
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