RLE Plots: Visualising Unwanted Variation in High Dimensional Data

Unwanted variation can be highly problematic and so its detection is often crucial. Relative log expression (RLE) plots are a powerful tool for visualising such variation in high dimensional data. We provide a detailed examination of these plots, with the aid of examples and simulation, explaining what they are and what they can reveal. RLE plots are particularly useful for assessing whether a procedure aimed at removing unwanted variation, i.e. a normalisation procedure, has been successful. These plots, while originally devised for gene expression data from microarrays, can also be used to reveal unwanted variation in many other kinds of high dimensional data, where such variation can be problematic.Comment: 9 pages, 3 figure

Thermodynamic versus Topological Phase Transitions: Cusp in the Kert\'esz Line

We present a study of phase transitions of the Curie--Weiss Potts model at (inverse) temperature $\beta$, in presence of an external field $h$. Both thermodynamic and topological aspects of these transitions are considered. For the first aspect we complement previous results and give an explicit equation of the thermodynamic transition line in the $\beta$--$h$ plane as well as the magnitude of the jump of the magnetization (for $q \geqslant 3)$. The signature of the latter aspect is characterized here by the presence or not of a giant component in the clusters of a Fortuin--Kasteleyn type representation of the model. We give the equation of the Kert\'esz line separating (in the $\beta$--$h$ plane) the two behaviours. As a result, we get that this line exhibits, as soon as $q \geqslant 3$, a very interesting cusp where it separates from the thermodynamic transition line

Phenotypic analysis of peripheral blood cell immunity in Italian patients with different varieties of oral lichen planus

Quantitative analysis of peripheral blood lymphocytes was carried out in 25 patients with atrophic-erosive type of oral lichen planus (OLP) (Group 1), in 28 patients with reticular-plaque like lesions of OLP (Group 2) and in 21 healthy patients (Group 3) by using flow cytometry. CD4 + subsets decreased significantly in patients with reticular-plaque like varieties when compared with healthy patients (Group 3) (One way analysis of variance p = 0.039; t-test with Bonferroni correction p< 0.05). Moreover, in patients with hyperkeratosic forms of OLP (Group 2) CD8 + cell populations were significantly higher than in controls (Group 3) (Kruskal-Wallis test p = 0.035; Mann-Whitney test with Bonferroni’s correction p< 0.0001) and consequently CD4/CD8 ratio was significantly lower in patients with reticular-plaque like lesions than in controls (Kruskal-Wallis test p = 0.01; Mann-Whitney test with Bonferroni’s correction p = 0.013). No statistical differences between patients of Group 1 (atrophic-erosive OLP) and the other two Groups (hyperkeratosic OLP and healthy controls) were detected. 40% of the patients of Group 1 were affected by chronic hepatopathies, most of which were related to hepatitis C virus (HCV), but the data were not substantially modified after adjustment for the patients with chronic liver disease HCV positive. There is no clear evidence that these results indicate the existence of a different pathogenetic mechanism between erosive-atrophic and hyperkeratosic types of OLP. On the other hand, these results and the previously reported immunohistochemical findings suggest that quantitative alterations of peripheral blood lymphocytes in hyperkeratosic varieties of OLP could represent a shift of CD4 + cells from the vascular to the oral mucosa compartment.Les lymphocytes du sang périphérique ont été évalués par cytométrie de flux dans deux groupes de malades porteurs d’un lichen plan de la muqueuse buccale: 25 à forme atrophique-érosive (Groupe 1), 28 à forme en réseaux ou en plaques blanches (Groupe 2), et chez 21 sujets sains (Groupe 3). Au terme de cette étude les différences les plus remarquables ont été les suivantes: diminution de la fraction CD4 + et une augmentation de la fraction CD8 + dans le Groupe 2 (réseaux et plaques blanches) comparés au Groupe 3 (contrôle), la différence est statistiquement significative (One ways analysis of variance p = 0.039, t test corrigé par Bonferroni p<0.05 pour CD4 + et Kruskal-Wallis test p = 0.035, Mann-Whitney test corrigé par Bonferroni p< 0.001 pour CD8 + ) par conséquent le rapport CD4/CD8 du Groupe 2 a été significativement plus bas par rapport au Groupe 3 (Kruskal-Wallis test p = 0.014; Mann-Whitney test corrigé par Bonferroni p = 0.013). Aucune autre différence significative entre les trois groupes n’a été observée, en particulier avec le Groupe 1 (formes atrophiques-érosives) dont il faut signaler que le 40% des sujets sont porteurs d’une hépatopathie chronique souvent due au virus de l’hépatite C. En conclusion la différence des résultats entre les groupes 1 et 2 ne permet pas d’affirmer l’existence d’une pathogénie différente entre les formes atrophiques-érosives et les formes en réseaux ou en plaques, elle est en accord avec les précédentes études en histo-immunochimie. Il est possible que la diminution des lymphocytes CD4 + soit secondaire au déplacement de cette population cellulaire du compartement vasculaire de la muqueuse affectée par le lichen plan.

Catalytic asymmetric C–C cross-couplings enabled by photoexcitation

Enantioselective catalytic processes are promoted by chiral catalysts that can execute a specific mode of catalytic reactivity, channeling the chemical reaction through a certain mechanistic pathway. Here, we show how by simply using visible light we can divert the established ionic reactivity of a chiral allyl–iridium(iii) complex to switch on completely new catalytic functions, enabling mechanistically unrelated radical-based enantioselective pathways. Photoexcitation provides the chiral organometallic intermediate with the ability to activate substrates via an electron-transfer manifold. This redox event unlocks an otherwise inaccessible cross-coupling mechanism, since the resulting iridium(ii) centre can intercept the generated radicals and undergo a reductive elimination to forge a stereogenic centre with high stereoselectivity. This photochemical strategy enables difficult-to-realize enantioselective alkyl–alkyl cross-coupling reactions between allylic alcohols and readily available radical precursors, which are not achievable under thermal activation. [Figure not available: see fulltext.

Cluster Percolation in O(n) Spin Models

The spontaneous symmetry breaking in the Ising model can be equivalently described in terms of percolation of Wolff clusters. In O(n) spin models similar clusters can be built in a general way, and they are currently used to update these systems in Monte Carlo simulations. We show that for 3-dimensional O(2), O(3) and O(4) such clusters are indeed the physical `islands' of the systems, i.e., they percolate at the physical threshold and the percolation exponents are in the universality class of the corresponding model. For O(2) and O(3) the result is proven analytically, for O(4) we derived it by numerical simulations.Comment: 11 pages, 8 figures, 2 tables, minor modification

Equianalgesia, opioid switch and opioid association in different clinical settings: a narrative review

Emergency or postoperative pain often represents an authentic challenge in patients who were already on opioid treatment for chronic pain. Thus. their management requires not only the physician's ability to treat acute pain. but also competence in switching the opioid that lost efficacy. Different aspects should be considered, such as opioids titration, switching, association and equianalgesia.The objective of this paper is to provide a narrative review. which has been elaborated and discussed among clinicians through an iterative process involving development and review of the draft during two web-based meetings and via email. This expert opinion aims to facilitate the correct opioid use through appropriate practices with a focus on pain treatment in emergency and postoperative pain.Equianalgesia tables were reviewed and integrated by clinicians and researchers with expertise in anesthesia, postoperative medicine, intensive care, emergency medicine pharmacology and addiction medicine. Special populations (liver/kidney failure. elder, pediatric, pregnancy/lactation) are discussed in detail along with other critical scenarios, such as: (i) rapid pain worsening in chronic pain (aggravating pain due to disease progression or tolerance development to analgesic therapy): (ii) acute pain on maintenance treatment: and (iii) pain management of complicated patients in emergency care.Extended and updated equianalgesia tables and conversion rates for 17 different opioid formulations (of 9 different molecules) are presented as follows.Opioids remain the class that best suits clinical needs of emergency and post-operative medicine. However, it should be stressed that equianalgesia can be affected by drug-to-drug interactions and pharmacological imprecision. in a complex field where clinical experience may be the main guiding principle

A lattice model for the line tension of a sessile drop

Within a semi--infinite thre--dimensional lattice gas model describing the coexistence of two phases on a substrate, we study, by cluster expansion techniques, the free energy (line tension) associated with the contact line between the two phases and the substrate. We show that this line tension, is given at low temperature by a convergent series whose leading term is negative, and equals 0 at zero temperature

System identification and nonlinear model predictive control with collision avoidance applied in Hexacopters UAVs

Accurate trajectory tracking is a critical property of unmanned aerial vehicles (UAVs) due to system nonlinearities, under-actuated properties and constraints. Specifically, the use of unmanned rotorcrafts with accuracy trajectory tracking controllers in dynamic environments has the potential to improve the fields of environment monitoring, safety, search and rescue, border surveillance, geology and mining, agriculture industry, and traffic control. Monitoring operations in dynamic environments produce significant complications with respect to accuracy and obstacles in the surrounding environment and, in many cases, it is difficult to perform even with state-of-the-art controllers. This work presents a nonlinear model predictive control (NMPC) with collision avoidance for hexacopters’ trajectory tracking in dynamic environments, as well as shows a comparative study between the accuracies of the Euler–Lagrange formulation and the dynamic mode decomposition (DMD) models in order to find the precise representation of the system dynamics. The proposed controller includes limits on the maneuverability velocities, system dynamics, obstacles and the tracking error in the optimization control problem (OCP). In order to show the good performance of this control proposal, computational simulations and real experiments were carried out using a six rotary-wind unmanned aerial vehicle (hexacopter—DJI MATRICE 600). The experimental results prove the good performance of the predictive scheme and its ability to regenerate the optimal control policy. Simulation results expand the proposed controller in simulating highly dynamic environments that showing the scalability of the controller