A Comparative Study on the Solution Techniques for Fiber Orientation in Two-Dimensional Converging and Diverging Flows

The two-dimensional steady flow of both infinite and finite aspect ratio (length to diameter ratio) fibers suspended in a Newtonian fluid is investigated numeri cally. Forty-five-degree convergent and divergent channel geometries are considered for the analysis. Due to symmetry, only half the channel geometry is considered and the ori entation field is assumed to be planar. The analysis is carried out for the creeping flows where the inertia terms are neglected. Numerical grid generation is used to generate the mesh, and the transformed governing equations in terms of the stream function are solved in the computational domain using a finite difference scheme. In this study, several solu tion strategies for solving the orientation field are investigated. The orientation of individ ual fibers are assumed to be governed by Jeffery's equation. The orientation field, which can be expressed in different forms (i.e., a unit vector, tensorial quantities, or an orienta tion distribution function), is specified by solving the orientation equations along particle paths. A tracing technique is implemented to obtain these particle paths for each grid point in the flow domain. The solution of the orientation field is obtained by using two basic techniques. First, a large number of fibers are considered, and by using analytical expres sions developed to describe the orientation state of one fiber, a statistical orientation distri bution function is generated. Second, tensorial quantities (both second- and fourth-order orientation tensors) are employed to solve for the orientation field. In order to overcome the closure problem occurring in the resulting orientation equations, quadratic approxima tions are used. Maximum orientation angles are reported from both the techniques, and their accuracies are investigated. The maximum orientation angles (i.e., preferred orienta tion) obtained from the second- and fourth-order tensorial solutions are observed to be identical. On the other hand, the degree of fiber alignments that are specified by the indi vidual tensor components differ considerably. Comparison of the solution techniques shows that the accuracy of the preferred angle obtained from statistical solution is depen dent on the number of fibers considered. In addition, the calculations for the finite fiber aspect ratio revealed some discrepancies between the statistical and tensorial results at the regions of rapid fiber tumbling.Yeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline

Buried solutions:How Maya urban life substantiates soil connectivity

Soils are a pivot of sustainable development. Yet, urban planning decisions persist in compromising the usability of the urban soils resource. Urban land cover expansion to accommodate an increasing population results in soil sealing. Concealment of and physical obstructions to soils prevent urban populations from engaging with their soil dependency. The concept of soil connectivity recognises that nurturing mutually beneficial soil–society relations is an essential dimension for achieving soil security. The concentrated populations of urban environments acutely require productive soil–society relations and offer the greatest potential for enhancing soil connectivity. Soil connectivity remains notably under-researched, however, resulting in deficient evidence to substantiate exactly how soil connectivity can contribute to sustaining urban life. The entanglement of soil and urban development has been critical throughout history, but seldom recognised in soil security discourse. We review the manifestation of effective soil connectivity in Precolumbian lowland Maya tropical urbanism. Archaeological evidence reveals, first, that lowland Maya urban settlement patterns largely preserved the availability, proximity, and accessibility of soils in the subdivision and configuration of urban open space. Second, Maya urban life included practices that proactively contributed to the formation of soils by adding to the stock of soils and improving beneficial soil properties of the thin and often nutrient-poor soils resulting from the regionally dominant karstic lithology. Third, a range of Maya landscape modifications and engineering practices enabled the preservation and protection of soils within urban environments. We derive evidence-based insights on an urban tradition that endured for well over two millennia by incorporating intensive soil–society relationships to substantiate the concept of soil connectivity. Inspiring urban planning to stimulate soil connectivity through enhancing the engagement with soils in urban life would promote soil security

Global urbanization and food production in direct competition for land:Leverage places to mitigate impacts on SDG2 and on the Earth System

Global urbanization and food production are in direct competition for land. This paper carries out a critical review of how displacing crop production from urban and peri-urban land to other areas – because of issues related to soil quality – will demand a substantially larger proportion of the Earth’s terrestrial land surface than the surface area lost to urban encroachment. Such relationships may trigger further distancing effects and unfair social-ecological teleconnections. It risks also setting in motion amplifying effects within the Earth System. In combination, such multiple stressors set the scene for food riots in cities of the Global South. Our review identifies viable leverage points on which to act in order to navigate urban expansion away from fertile croplands. We first elaborate on the political complexities in declaring urban and peri-urban lands with fertile soils as one global commons. We find that the combination of an advisory global policy aligned with regional policies enabling robust common properties rights for bottom-up actors and movements in urban and peri-urban agriculture (UPA) as multi-level leverage places to intervene. To substantiate the ability of aligning global advisory policy with regional planning, we review both past and contemporary examples where empowering local social-ecological UPA practices and circular economies have had a stimulating effect on urban resilience and helped preserve, restore, and maintain urban lands with healthy soils

Developing Evidence-Based Design Guidelines For Medical/ Surgical Hospital Patient Rooms That Meet The Needs Of Staff, Patients, And Visitors

Objectives: This research investigated medical/surgical (Med/Surg) patient room design to accommodate the needs of hospital staff, while at the same time accommodating the needs of patients and their visitors. Background: Designing hospital patient rooms that provide a comfortable healing experience for patients, while at the same time meeting the needs of the hospital staff, is a challenging process. Prior research has shown that many hospital patient room designs adversely affect the ability of hospital staff to perform their tasks effectively, efficiently, and safely. Method: Twenty-seven design sessions were conducted in which 104 participants, representing 24 different occupations, worked in small mixed occupational groups to design an ideal single patient Med/Surg patient room to fit their collective needs using a full-scale mock-up. During analysis, the investigators reduced the resulting 27 room designs to 5 hybrid designs that were sequentially reviewed by patients and visitors and by staff to address design conflicts. Results: This design process identified 51 desirable room design features that were incorporated into 66 evidence-based design guidelines for the different areas within the Med/Surg patient room including the entry way (16 guidelines), the patient clinical area (22 guidelines), the bathroom (17 guidelines), the family area (8 guidelines), and storage areas for patients and their visitors (3 guidelines). Conclusions: The guidelines developed through this study identified many opportunities for improving the design of hospital Med/Surg rooms to allow staff to be more effective, efficient, and safer, while at the same time addressing the design needs of patients and their visitors

Search for Heavy Neutral and Charged Leptons in e+ e- Annihilation at LEP

A search for exotic unstable neutral and charged heavy leptons as well as for stable charged heavy leptons is performed with the L3 detector at LEP. Sequential, vector and mirror natures of heavy leptons are considered. No evidence for their existence is found and lower limits on their masses are set

Sequential, Multiple-Assignment, Randomized Trials for COMparing Personalized Antibiotic StrategieS (SMART-COMPASS)

Patient management is not based on a single decision. Rather, it is dynamic: Based on a sequence of decisions, with therapeutic adjustments made over time. Adjustments are personalized: Tailored to individual patients as new information becomes available. However, strategies allowing for such adjustments are infrequently studied. Traditional antibiotic trials are often nonpragmatic, comparing drugs for definitive therapy when drug susceptibilities are known. COMparing Personalized Antibiotic StrategieS (COMPASS) is a trial design that compares strategies consistent with clinical practice. Strategies are decision rules that guide empiric and definitive therapy decisions. Sequential, multiple-assignment, randomized (SMART) COMPASS allows evaluation when there are multiple, definitive therapy options. SMART COMPASS is pragmatic, mirroring clinical, antibiotic-treatment decision-making and addressing the most relevant issue for treating patients: Identification of the patient-management strategy that optimizes the ultimate patient outcomes. SMART COMPASS is valuable in the setting of antibiotic resistance, when therapeutic adjustments may be necessary due to resistance

International Epidemiology of Carbapenemase-Producing Escherichia coli

Background: Carbapenemase-producing (CP) Escherichia coli (CP-Ec) are a global public health threat. We aimed to describe the clinical and molecular epidemiology and outcomes of patients from several countries with CP-Ec isolates obtained from a prospective cohort. Methods: Patients with CP-Ec were enrolled from 26 hospitals in 6 countries. Clinical data were collected, and isolates underwent whole-genome sequencing. Clinical and molecular features and outcomes associated with isolates with or without metallo-β-lactamases (MBLs) were compared. The primary outcome was desirability of outcome ranking (DOOR) at 30 days after the index culture. Results: Of the 114 CP-Ec isolates in Consortium on resistance against carbapenems in Klebsiella and other Enterobacterales-2 (CRACKLE-2), 49 harbored an MBL, most commonly blaNDM-5 (38/49, 78%). Strong regional variations were noted with MBL-Ec predominantly found among patients in China (23/49). Clinically, MBL-Ec were more often from urine sources (49% vs 29%), less often met criteria for infection (39% vs 58%, P =. 04), and had lower acuity of illness when compared with non-MBL-Ec. Among patients with infection, the probability of a better DOOR outcome for a randomly selected patient with MBL-Ec as compared with non-MBL-Ec was 62% (95% CI: 48.2-74.3%). Among infected patients, non-MBL-Ec had increased 30-day (26% vs 0%; P =. 02) and 90-day (39% vs 0%; P =. 001) mortality compared with MBL-Ec. Conclusions: Emergence of CP-Ec was observed with important geographic variations. Bacterial characteristics, clinical presentations, and outcomes differed between MBL-Ec and non-MBL-Ec. Mortality was higher among non-MBL isolates, which were more frequently isolated from blood, but these findings may be confounded by regional variations