Symmetry breaking phenomena in thermovibrationally driven particle accumulation structures

Following the recent discovery of new three-dimensional particle attractors driven by joint (fluid) thermovibrational and (particle) inertial effects in closed cavities with various shapes and symmetries [M. Lappa, Phys. Fluids 26(9), 093301 (2014); ibid. 31(7), 073303 (2019)], the present analysis continues this line of inquiry by probing influential factors hitherto not considered; among them, the role of the steady component of thermovibrational convection, i.e., the time-averaged velocity field that is developed by the fluid due to the non-linear nature of the overarching balance equations. It is shown how this apparently innocuous problem opens up a vast parameter space, which includes several variables, comprising (but not limited to) the frequency of vibrations, the so-called "Gershuni number,"the size of particles (Stokes number), and their relative density with respect to the surrounding fluid (density ratio). A variety of new particle structures (2D and 3D) are uncovered and a complete analysis of their morphology is presented. The results reveal an increase in the multiplicity of solutions brought in by the counter-intuitive triadic relationship among particle inertial effects and the instantaneous and time-averaged convective thermovibrational phenomena. Finally, a universal formula is provided that is able to predict correctly the time required for the formation of all the observed structures

Genetic isolation by distance and landscape connectivity in the American marten ( Martes americana )

Empirical studies of landscape connectivity are limited by the difficulty of directly measuring animal movement. ‘Indirect' approaches involving genetic analyses provide a complementary tool to ‘direct' methods such as capture-recapture or radio-tracking. Here the effect of landscape on dispersal was investigated in a forest-dwelling species, the American marten (Martes americana) using the genetic model of isolation by distance (IBD). This model assumes isotropic dispersal in a homogeneous environment and is characterized by increasing genetic differentiation among individuals separated by increasing geographic distances. The effect of landscape features on this genetic pattern was used to test for a departure from spatially homogeneous dispersal. This study was conducted on two populations in homogeneous vs. heterogeneous habitat in a harvested boreal forest in Ontario (Canada). A pattern of IBD was evidenced in the homogeneous landscape whereas no such pattern was found in the near-by harvested forest. To test whether landscape structure may be accountable for this difference, we used effective distances that take into account the effect of landscape features on marten movement instead of Euclidean distances in the model of isolation by distance. Effective distances computed using least-cost modeling were better correlated to genetic distances in both landscapes, thereby showing that the interaction between landscape features and dispersal in Martes americana may be detected through individual-based analyses of spatial genetic structure. However, the simplifying assumptions of genetic models and the low proportions in genetic differentiation explained by these models may limit their utility in quantifying the effect of landscape structur

Role of HOXA7 to HOXA13 and PBX1 genes in various forms of MRKH syndrome (congenital absence of uterus and vagina)

The Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome refers to the congenital absence or severe hypoplasia of the female genital tract, often described as uterovaginal aplasia which is the prime feature of the syndrome. It is the second cause of primary amenorrhea after gonadal dysgenesis and occurs in ~1 in 4500 women. Aetiology of this syndrome remains poorly understood. Frequent association of other malformations with the MRKH syndrome, involving kidneys, skeleton and ears, suggests the involvement of major developmental genes such as those of the HOX family. Indeed mammalian HOX genes are well known for their crucial role during embryogenesis, particularly in axial skeleton, hindbrain and limb development. More recently, their involvement in organogenesis has been demonstrated notably during urogenital differentiation. Although null mutations of HOX genes in animal models do not lead to MRKH-like phenotypes, dominant mutations in their coding sequences or aberrant expression due to mutated regulatory regions could well account for it. Sequence analysis of coding regions of HOX candidate genes and of PBX1, a likely HOX cofactor during Müllerian duct differentiation and kidney morphogenesis, did not reveal any mutation in patients showing various forms of MRKH syndrome. This tends to show that HOX genes are not involved in MRKH syndrome. However it does not exclude that other mechanisms leading to HOX dysfunction may account for the syndrome

Classification neuronale des fonds marins par modélisation AutoRégressive bidimensionnelle

Cette étude présente une méthode simple et efficace de caractérisation de textures couplée à un modèle neuronal dans le but d'obtenir une classification des fonds marins en imagerie Sonar. Un modèle autorégressif (AR) linéaire est appliqué à l'image Sonar pour en extraire des attributs caractéristiques significatifs. Les performances de la méthode autorégressive sont évaluées à l'aide d'un classifieur neuronal, de type Perceptron MultiCouche (PMC), qui distingue quatre types de fonds : cailloux, dunes, rides de sable et sable. Les bons taux de classification rencontrés pour chaque type de fond sur une base distincte de la base d'apprentissage sont présentés. Une originalité de l'approche réside dans le couplage performant obtenu entre modélisation AR et module neuronal pour l'application concernée

Implications of preoperative depression for lumbar spine surgery outcomes: A systematic review and meta-analysis

IMPORTANCE: Comorbid depression is common among patients with degenerative lumbar spine disease. Although a well-researched topic, the evidence of the role of depression in spine surgery outcomes remains inconclusive. OBJECTIVE: To investigate the association between preoperative depression and patient-reported outcome measures (PROMs) after lumbar spine surgery. DATA SOURCES: A systematic search of PubMed, Cochrane Database of Systematic Reviews, Embase, Scopus, PsychInfo, Web of Science, and ClinicalTrials.gov was performed from database inception to September 14, 2023. STUDY SELECTION: Included studies involved adults undergoing lumbar spine surgery and compared PROMs in patients with vs those without depression. Studies evaluating the correlation between preoperative depression and disease severity were also included. DATA EXTRACTION AND SYNTHESIS: All data were independently extracted by 2 authors and independently verified by a third author. Study quality was assessed using Newcastle-Ottawa Scale. Random-effects meta-analysis was used to synthesize data, and I2 was used to assess heterogeneity. Metaregression was performed to identify factors explaining the heterogeneity. MAIN OUTCOMES AND MEASURES: The primary outcome was the standardized mean difference (SMD) of change from preoperative baseline to postoperative follow-up in PROMs of disability, pain, and physical function for patients with vs without depression. Secondary outcomes were preoperative and postoperative differences in absolute disease severity for these 2 patient populations. RESULTS: Of the 8459 articles identified, 44 were included in the analysis. These studies involved 21 452 patients with a mean (SD) age of 57 (8) years and included 11 747 females (55%). Among these studies, the median (range) follow-up duration was 12 (6-120) months. The pooled estimates of disability, pain, and physical function showed that patients with depression experienced a greater magnitude of improvement compared with patients without depression, but this difference was not significant (SMD, 0.04 [95% CI, -0.02 to 0.10]; I2 = 75%; P = .21). Nonetheless, patients with depression presented with worse preoperative disease severity in disability, pain, and physical function (SMD, -0.52 [95% CI, -0.62 to -0.41]; I2 = 89%; P \u3c .001), which remained worse postoperatively (SMD, -0.52 [95% CI, -0.75 to -0.28]; I2 = 98%; P \u3c .001). There was no significant correlation between depression severity and the primary outcome. A multivariable metaregression analysis suggested that age, sex (male to female ratio), percentage of comorbidities, and follow-up attrition were significant sources of variance. CONCLUSIONS AND RELEVANCE: Results of this systematic review and meta-analysis suggested that, although patients with depression had worse disease severity both before and after surgery compared with patients without depression, they had significant potential for recovery in disability, pain, and physical function. Further investigations are needed to examine the association between spine-related disability and depression as well as the role of perioperative mental health treatments

Simultaneous Quantification and Visualization of Titanium Dioxide Nanomaterial Uptake at the Single Cell Level in an In Vitro Model of the Human Small Intestine

International audienceUseful properties render titanium dioxide nanomaterials (NMs) to be one of the most commonly used NMs worldwide. TiO2 powder is used as food additives (E171), which may contain up to 36% nanoparticles. Consequently, humans could be exposed to comparatively high amounts of NMs that may induce adverse effects of chronic exposure conditions. Visualization and quantification of cellular NM uptake as well as their interactions with biomolecules within cells are key issues regarding risk assessment. Advanced quantitative imaging tools for NM detection within biological environments are therefore required. A combination of the label-free spatially resolved dosimetric tools, microresolved particle induced X-ray emission and Rutherford backscattering, together with high resolution imaging techniques, such as time-of-flight secondary ion mass spectrometry and transmission electron microscopy, are applied to visualize the cellular translocation pattern of TiO2 NMs and to quantify the NM-load, cellular major, and trace elements in differentiated Caco-2 cells as a function of their surface properties at the single cell level. Internalized NMs are not only able to impair the cellular homeostasis by themselves, but also to induce an intracellular redistribution of metabolically relevant elements such as phosphorus, sulfur, iron, and copper

Particle Vibration, an instrument to study particle accumulation structures on board the International Space Station

The scientific and technological aspects of the PARTICLE VIBRATION Project (also known as T-PAOLA i.e. "Thermovibrationally-driven Particle self-Assembly and Ordering mechanisms in Low grAvity") are described in detail. The project relies on the combined use of the Selectable Optical Diagnostics Instrument (SODI), a Class-2 device developed by ESA for scientific experiments in the field of fluids on board the International Space Station, and the Microgravity Science Glovebox (MSG), a Class-1 general purpose facility under the responsibility of NASA. The related modular architecture has recently been expanded under the umbrella of new scientific research funded by the UK Space Agency to allow for a novel class of experiments dealing with multiphase (solid-liquid) flows. The final aim of this microgravity project is the identification of new dispersed-phase self-organization phenomena driven by the application of vibrations and the ensuing development of new contactless particle manipulations strategies. In the present paper, emphasis is given to the related space hardware and software, the experiment protocol, the ground tests and procedures and all the adaptations that had to be implemented to overcome a number of technological and physical issues, both general and system-specific

Depauperate Avifauna in Plantations Compared to Forests and Exurban Areas

Native forests are shrinking worldwide, causing a loss of biological diversity. Our ability to prioritize forest conservation actions is hampered by a lack of information about the relative impacts of different types of forest loss on biodiversity. In particular, we lack rigorous comparisons of the effects of clearing forests for tree plantations and for human settlements, two leading causes of deforestation worldwide. We compared avian diversity in forests, plantations and exurban areas on the Cumberland Plateau, USA, an area of global importance for biodiversity. By combining field surveys with digital habitat databases, and then analyzing diversity at multiple scales, we found that plantations had lower diversity and fewer conservation priority species than did other habitats. Exurban areas had higher diversity than did native forests, but native forests outscored exurban areas for some measures of conservation priority. Overall therefore, pine plantations had impoverished avian communities relative to both native forests and to exurban areas. Thus, reports on the status of forests give misleading signals about biological diversity when they include plantations in their estimates of forest cover but exclude forested areas in which humans live. Likewise, forest conservation programs should downgrade incentives for plantations and should include settled areas within their purview