Rurality Versus Readiness: The Relationship Between State-Level Connection and Capacity Variables and the Management of Medical Stockpiles for a Public Health Emergency

This study investigates what factors contributed to the score a state received for managing its medical countermeasures stockpile pre-COVID-19. It is particularly interested in the relationship between a state’s level of rural population and its countermeasure management capacity. A fixed-effects regression analysis was run using data from 2016 to 2019 to test for a relationship between the percentage of rural population in a state and the states’ countermeasures management score, while controlling for other relevant social, economic, and political variables such as level of social associations, the segregation index, and the level of income inequality. Rurality and physicians per capita proved to be significant and negative. A subsequent analysis found that states with higher levels of rural populations have lower levels of COVID-19 vaccinations, even accounting for effective countermeasure management. This points to rural states having challenges in regard to medical countermeasures that cannot be completely solved with technocratic solutions.

Smartphone Application for Determining the Segregation Index of Lightweight Aggregate Concrete

Due to the low density of the aggregates and the longer mixing times, lightweight aggregate concrete (LWAC) is susceptible to segregation of the aggregates. Several studies have proposed different methods to estimate the segregation of concrete because segregation affects strength and durability in structures. Image analysis techniques have become very popular for quickly analysing different materials and, together with the widespread use of mobile applications, can make it much easier for engineers to obtain parameters that identify concrete segregation. The aim of this work was the development of a mobile application to photograph the section of a concrete specimen and indicate the segregation values. A simple, fast, and effective application was implemented, and the results were validated with other previously published results, which can facilitate the task of engineers and researchers to determine the segregation of concrete.

Measuring the Degree of Overlap and Segregation among Multiple Probabilistic Home Ranges: A New Index with Illustrative Application to the Lesser Kestrel Falco naumanni

Home range overlap/segregation has several important applications to wildlife conservation and management. In this work, we first address the issue of measuring the degree of overlap/segregation among an arbitrarily large number (i.e., n ≥ 2) of probabilistic animal home ranges (i.e., utilization distributions). This subject matter has recently been solved for home ranges measured as polygons (e.g., percent minimum convex polygons and multinuclear cores) but not yet for probabilistic ones. Accordingly, we introduce a novel index named the PGOI (probabilistic general overlap index), and its complement, the PGSI (probabilistic general segregation index), an index for computation of probabilistic home range overlap/segregation at individual, population and species levels. Whatever the number of probabilistic home ranges, the PGOI returns a single score ranging in the [0, 100] interval. We applied the PGOI to five lesser kestrels (Falco naumanni) at Santeramo in Colle (Apulia region; Southern Italy) as a case study. Our new index can be applied to any animal species and to home ranges derived from any type of probabilistic home range estimator.

Multi-occupation segregation through London's tube network

As an extension of public space, the public transport system in modern society is an arena for cross-group interactions. Uncovering social segregation in public transport space is an essential step in shaping a socially sustainable transport system. Based on 2011 origin–destination flow data for London, we simulate the working flows between each pair of connected tube stations for every occupation with minimised transfer times and travelling hours and calculate the multi-occupation segregation index for all tube stations and segments. This segregation index captures the density and diversity aspects of the working population. The results demonstrate that segregation levels vary significantly across stations, lines, and segments. Transfer stations and tube segments in the city centre do not necessarily have lower levels of segregation. Those stations or segments close to a terminus can also be socially inclusive, e.g., Heathrow. Victoria is the line with the lowest levels of segregation, and Green Park is the most socially inclusive station during commuting peaks. The proposed mapping approach demonstrates the spatial complexity in the social performance of the public transport system and provides a tool for implementing relevant policy with improved precision.

Rheology, fresh and hardened properties of self-consolidating concrete utilizing metal and PVA polymer fibers

Fiber reinforced self-consolidating concrete (FRSCC) has a tremendous potential to be used in construction industry as it combines the advantagees of both self-consolidating concrete (SCC) and fiber reinforced concrete (FRC). 18 concrete mixtures were developed by incorporating differenct volumes (0 to 0.3) of polyvinyl alchohol (PVA) and metallic fibers. Fresh, rheological, mechanical and durability (in terms of chloride penetration resistance) properties of all FRSCC mixtures were evaluated. The influences of fiber types/size/ dosages and fiber combination (used in hybrid mixes) on fresh (slump flow, L-box passing ability, V-funnel flow time and segregation index), rheological (plastic viscosity and yield stress) and hardened (fracture energy and compressive/flexural/splitting tensile strength) properties were critically analyzed to examine the relationships among various properties as well as to suggest suitable FRSCC mixtures. The fibers (especially metallic ones) wre more effective in increasing the fracture energy of FRSCC than compressive/splitting tensile/flexural strength. A fracture energy gain of about 730% was observed (which is substantial) compared to 10% of compressive strength, 39% of splitting tensil strength and 124% of flexural strength. The improved strength and fracture energy of FRSCC mixtures can significantly reduce the amount of tensile reinforcement and subsantially increase the energy absorbing capacity of concrete structures.

Rheology, fresh and hardened properties of self-consolidating concrete utilizing metal and PVA polymer fibers

Fiber reinforced self-consolidating concrete (FRSCC) has a tremendous potential to be used in construction industry as it combines the advantagees of both self-consolidating concrete (SCC) and fiber reinforced concrete (FRC). 18 concrete mixtures were developed by incorporating differenct volumes (0 to 0.3) of polyvinyl alchohol (PVA) and metallic fibers. Fresh, rheological, mechanical and durability (in terms of chloride penetration resistance) properties of all FRSCC mixtures were evaluated. The influences of fiber types/size/ dosages and fiber combination (used in hybrid mixes) on fresh (slump flow, L-box passing ability, V-funnel flow time and segregation index), rheological (plastic viscosity and yield stress) and hardened (fracture energy and compressive/flexural/splitting tensile strength) properties were critically analyzed to examine the relationships among various properties as well as to suggest suitable FRSCC mixtures. The fibers (especially metallic ones) wre more effective in increasing the fracture energy of FRSCC than compressive/splitting tensile/flexural strength. A fracture energy gain of about 730% was observed (which is substantial) compared to 10% of compressive strength, 39% of splitting tensil strength and 124% of flexural strength. The improved strength and fracture energy of FRSCC mixtures can significantly reduce the amount of tensile reinforcement and subsantially increase the energy absorbing capacity of concrete structures.

The Invisible Boundaries in the City

1. Perhaps physical frontiers are less important since somehow the world has become a global entity, in which information passes through the physical walls. Many of them have been destroyed (Berlin) and some others such as that of Cyprus resist, but they are certainly less effective than in the past. The major concern of the future is the identification of invisible borders within the cities. It is difficult to identify exclusion, and marginalization is hiding within the cities, even in the weal- thiest ones.The spaces of the cities have invisible borders, but they are not easy to cross. 2. An MIT study (Xu Y, Belyi A, Santi P, Ratti C. 2019) highlights these problems after processing data on human movements, social networks connections and the socio-economic status of people, the document proposes two indices to measure segregation in Singapore. The index segregation of communication measures the relationship between people within each so- cial network, considering the frequency of communication and the socio-economic attributes of each person. The physical segregation index indicates the social exposure which people have towards each other belonging to similar and different socio-economic groups as they move more and more around the city. 3. The MIT study shows how it is possible, through the management of big data, to be able to bring out invisible marginalization situations which can not be seen in other ways. 4. The “documedial process” (Ferraris, Paini, 2018) in which the digital breakthrough has transformed the city, allows not only to bring out areas of border and exclusion but lays the foundations for an analysis of reality capable of highlighting cultural isolation.

Local Segregation Scores of Entropy-Based Segregation Indices

The Mutual Information segregation index M can be decomposed into a weighted average of local segregation scores. This useful property can be used to assess whether some units (say, occupations or geographic areas) contribute more to overall segregation than other units. The related segregation index H is a normalized version of the M index, such that the index is constrained to fall between 0 and 1. The question addressed in this paper is whether local segregation scores of the M index can be normalized in a similar way, to arrive at useful local segregation scores for the H index. The paper shows that it is not possible to obtain normalized local segregation scores that fall between 0 and 1 and that also aggregate to the H index. The one exception to this is the situation when all groups in the population are exactly of equal size. It is also (trivially) possible to decompose the H index into weighted local segregation scores, however, they have the same problems of interpretation as the local segregation scores of the M index.

Stability Evaluation and Mechanism of Asphalts Modified With Various Rubber Powder Contents

Ground tires are one of the main sources of urban solid waste. Rubber powder-modified asphalt provides an effective method to solve the problem, and it presents good high- and low-temperature performance in sustainable pavement construction. However, the storage properties of rubber powder-modified asphalts prepared from the traditional low-temperature shear mixing method are unstable, which restricts their application. In this study, four test methods (the softening-point test; the dynamic shear rheological test; the Laboratory Asphalt Stability Test; and fluorescence image analysis) and six evaluation indexes (the softening-point difference Sdiff, the segregation percentage Sp, the segregation index Ise, the segregation rate Rs, the degradation rate Rd, and the stability index Ist) were employed to analyze the storage abilities of asphalts modified by various activated rubber powder contents. The results show that the storage properties have a positive correlation with rubber powder content in the modified asphalt, and a rubber powder content of 60% is proven to be the optimum mixing amount. The rubber powders can distribute uniformly in the asphalt matrix when mixed below the optimum mixing amount; otherwise a rubber powder agglomeration is formed. The quantitative morphology analysis results are in good agreement with the laboratory test conclusions. The activated rubber powder shows better compatibility compared with ordinary rubber powders and presents a promising method to treat waste ground tires.