Point-particle drag, lift, and torque closure models using machine learning: hierarchical approach and interpretability

Developing deterministic neighborhood-informed point-particle closure models using machine learning has garnered interest in recent times from dispersed multiphase flow community. The robustness of neural models for this complex multi-body problem is hindered by the availability of particle-resolved data. The present work addresses this unavoidable limitation of data paucity by implementing two strategies: (i) by using a rotation and reflection equivariant neural network and (ii) by pursuing a physics-based hierarchical machine learning approach. The resulting machine learned models are observed to achieve a maximum accuracy of 85% and 96% in the prediction of neighbor-induced force and torque fluctuations, respectively, for a wide range of Reynolds number and volume fraction conditions considered. Furthermore, we pursue force and torque network architectures that provide universal prediction spanning a wide range of Reynolds number ($0.25 \leq Re \leq 250$) and particle volume fraction ($0 \leq \phi \leq 0.4$). The hierarchical nature of the approach enables improved prediction of quantities such as streamwise torque, by going beyond binary interactions to include trinary interactions

Could Nanotheranostics be the Answer to the Coronavirus Crisis?

The COVID-19 pandemic is expanding worldwide. This pandemic associated with COVID-19 placed the spotlight on how bacterial (e.g., methicillin-resistant Staphylococcus aureus) co-infections may impact responses to coronavirus. In this review the ways in which nanoparticles can contain and rapidly diagnose COVID-19 under the umbrella of nanotheranostics (i.e., smart, single agents combining nanodiagnostics and nanotherapeutics) are elaborated. The present work provides new insights into the promising incorporation of antiviral nanotheranostics into nanostructured materials, including electrospun fibers with tailored pore sizes and hydrophobicity, namely "superhydrophobic self-disinfecting electrospun facemasks/fabrics (SSEF)." SSEFs are proposed as smart alternatives to address the drawbacks of N95 respirators. The challenges of coronavirus containment are underscored, literature is reviewed, and "top-five suggestions" for containing COVID-19 are offered, including: i) preventive appraisals-avoiding needless hospital admission and practicing frequent hand washing (from 20 to 60 s). ii) Diagnostics-highly recommending nanodiagnostics, detecting COVID-19 within 10 min. iii) Therapeutics-expanding nanotherapeutics to treat COVID-19 and bacterial co-infections after safety assessments and clinical trials. iv) Multipronged and multinational, including China, collaborative appraisals. v) Humanitarian compassion to traverse this pandemic in a united way.Peer reviewe

Effect of Selected Fruit Wastes on Hematological Parameters in DEN-Induced Hepatic Carcinoma in Rats

Fruits and processed food demand has greatly increased due to which a huge amount of fruit waste is generated. In this study, the effect of the ethanolic extract of waste material Punica granatum (pomegranate) peel and Vitis vinifera (grapes) seeds was evaluated on hematological parameters in Wistar rats with diethylnitrosamine (DEN) induced hepatocellular carcinoma. The treatments were divided into four groups: Group 1 was untreated while Groups 2-4 received 200 mg/kg body weight of DEN by single intraperitoneal administration. Groups 3 and 4 received DEN and co-treated with 400 mg/kg pomegranate peel extract and 400 mg/kg grape seed extract, respectively. There was a significant decrease in the body weight of animals in Group 2, while Group 3 and 4 animals were found to have a significant rise in body weight. The weight of the liver was significantly increased in the cancer-bearing group and its size was significantly reverted in the treated groups. The kidney and spleen showed a significant decrease in size of cancer-induced groups, and these organs significantly increased in treated groups. Hemoglobin, red blood cells (RBC), neutrophil, packed cell volume (PCV), Mean corpuscular volume (MCV) and mean corpuscular haemoglobin (MCH) were significantly reduced in Group 2 animals compared to Group 1. The levels of white blood cells (WBC) and erythrocyte sedimentation rate were increased significantly in Group 2 animals relating to Group 1. Both in Group 3 and 4 animals, these changes were reversed. Results reveal that selected fruit wastes alleviate vital hematological parameters in hepatocellular carcinoma-induced rats

Convection in colloidal suspensions with particle-concentration-dependent viscosity

The onset of thermal convection in a horizontal layer of a colloidal suspension is investigated in terms of a continuum model for binary-fluid mixtures where the viscosity depends on the local concentration of colloidal particles. With an increasing difference between the viscosity at the warmer and the colder boundary the threshold of convection is reduced in the range of positive values of the separation ratio psi with the onset of stationary convection as well as in the range of negative values of psi with an oscillatory Hopf bifurcation. Additionally the convection rolls are shifted downwards with respect to the center of the horizontal layer for stationary convection (psi>0) and upwards for the Hopf bifurcation (psi<0).Comment: 8 pages, 6 figures, submitted to European Physical Journal

The Abundance of Pink-Pigmented Facultative Methylotrophs in the Root Zone of Plant Species in Invaded Coastal Sage Scrub Habitat

Pink-pigmented facultative methylotrophic bacteria (PPFMs) are associated with the roots, leaves and seeds of most terrestrial plants and utilize volatile C1 compounds such as methanol generated by growing plants during cell division. PPFMs have been well studied in agricultural systems due to their importance in crop seed germination, yield, pathogen resistance and drought stress tolerance. In contrast, little is known about the PPFM abundance and diversity in natural ecosystems, let alone their interactions with non-crop species. Here we surveyed PPFM abundance in the root zone soil of 5 native and 5 invasive plant species along ten invasion gradients in Southern California coastal sage scrub habitat. PPFMs were present in every soil sample and ranged in abundance from 102 to 105 CFU/g dry soil. This abundance varied significantly among plant species. PPFM abundance was 50% higher in the root zones of annual or biennial species (many invasives) than perennial species (all natives). Further, PPFM abundance appears to be influenced by the plant community beyond the root zone; pure stands of either native or invasive species had 50% more PPFMs than mixed species stands. In sum, PPFM abundance in the root zone of coastal sage scrub plants is influenced by both the immediate and surrounding plant communities. The results also suggest that PPFMs are a good target for future work on plant-microorganism feedbacks in natural ecosystems

Heme Mediated STAT3 Activation in Severe Malaria

The mortality of severe malaria [cerebral malaria (CM), severe malaria anemia (SMA), acute lung injury (ALI) and acute respiratory distress syndrome (ARDS)] remains high despite the availability associated with adequate treatments. Recent studies in our laboratory and others have revealed a hitherto unknown correlation between chemokine CXCL10/CXCR3, Heme/HO-1 and STAT3 and cerebral malaria severity and mortality. Although Heme/HO-1 and CXCL10/CXCR3 interactions are directly involved in the pathogenesis of CM and fatal disease, the mechanism dictating how Heme/HO-1 and CXCL10/CXCR3 are expressed and regulated under these conditions is still unknown. We therefore tested the hypothesis that these factors share common signaling pathways and may be mutually regulated.We first clarified the roles of Heme/HO-1, CXCL10/CXCR3 and STAT3 in CM pathogenesis utilizing a well established experimental cerebral malaria mouse (ECM, P. berghei ANKA) model. Then, we further determined the mechanisms how STAT3 regulates HO-1 and CXCL10 as well as mutual regulation among them in CRL-2581, a murine endothelial cell line.The results demonstrate that (1) STAT3 is activated by P. berghei ANKA (PBA) infection in vivo and Heme in vitro. (2) Heme up-regulates HO-1 and CXCL10 production through STAT3 pathway, and regulates CXCL10 at the transcriptional level in vitro. (3) HO-1 transcription is positively regulated by CXCL10. (4) HO-1 regulates STAT3 signaling.Our data indicate that Heme/HO-1, CXCL10/CXCR3 and STAT3 molecules as well as related signaling pathways play very important roles in the pathogenesis of severe malaria. We conclude that these factors are mutually regulated and provide new opportunities to develop potential novel therapeutic targets that could be used to supplement traditional prophylactics and treatments for malaria and improve clinical outcomes while reducing malaria mortality. Our ultimate goal is to develop novel therapies targeting Heme or CXCL10-related biological signaling molecules associated with development of fatal malaria