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We study how the speckle contrast depends on scatterer velocity, with the goal of further developing laser speckle imaging as a quantitative measurement technique. To that end, we perform interferometric computer simulations on a dilute plug flow. The results of our numerical experiment, that we compare with known analytical expressions to confirm their veracity, match well at low velocities with the Gaussian expression. Finally, we address the issue of how velocity depends on speckle decorrelation time, and show that the speckle size is most likely the relevant connecting length scale.

Graphene has triggered enormous interest in, and exploration of, its applications in diverse areas of science and technology due to its unique properties. While graphene has displayed great potential as a nano-delivery system for drugs and biomolecules in biomedicine, its application as a nanocarrier in agriculture has only begun to be explored. Conventional fertilizers and agricultural delivery systems have a number of disadvantages, such as: fast release of the active ingredient, low delivery efficiency, rapid degradation and low stability that often leads to their over-application and consequent environmental problems. Advanced nano fertilizers with high carrier efficiency and slow and controlled release are now considered the gold standard for promoting agricultural sustainability while protecting the environment. Graphene's attractive properties include large surface area, chemical stability, mechanical stability, tunable surface chemistry and low toxicity making it a promising material on which to base agricultural delivery systems. Recent research has demonstrated considerable success in the use of graphene for agricultural applications, including its utilization as a delivery vehicle for plant nutrients and crop protection agents, as well as in post-harvest management of crops. This review, therefore, presents a comprehensive overview of the current status of graphene-based nanocarriers in agriculture. Additionally, the review outlines the surface functionalization methods used for effective molecular delivery, various strategies for nano-vehicle design and the underlying features necessary for a graphene-based agro-delivery system. Finally, the review discusses directions for further research in optimization of graphene-based nanocarriers. [ABSTRACT FROM AUTHOR]

This paper, a first‐person account, describes a community psychology‐aligned intervention into a precalculus mathematics class at an Hispanic Serving Research Institution. The intervention was designed because the standard precalculus mathematics class had a high failure rate, especially for Latinx students, which was serving as a barrier for declaration of a Science, Technology, Engineering, or Mathematics major. The high failure rate indicates a structural problem that requires a structural intervention. The paper is coauthored with the teaching team, undergraduates who had taken the course, a graduate student who evaluated the class, and a community psychologist. We describe the ways that the new course, the College Math Academy, transformed the social environment through capacity building, providing access to valued resources for historically marginalized groups, facilitating opportunities to critique dominant power structures, prioritizing perspectives and experiences of people of color, and promoting understanding of how various social forces shape culture and values. The course also decentered white educational norms via adapting decoloniality and liberatory practices. In turn, each person describes their experience of the course. We draw on the first‐person accounts to show how they illustrate a transformative, decolonial, and liberatory social environment. We end with implications for how community psychologists can work in their universities to support structural change. Highlights: Changes to Precalculus class to better serve Latinx students.First person account of how structural course change shifted the classroom experience for students.Integration of a decolonial social enviornment intervention into a college math class. [ABSTRACT FROM AUTHOR]

The present paper attempts to examine the occurrences of epidemic and pandemic in the prehistoric times through use of molecular methods and archaeological evidences. The pandemic situation of the world created by SARS CoV-2 causing COVID-19 infection triggered the interest in the mind of this author to delve into the prehistoric world about the etiology of such diseases. The basic questions are whether any such pandemic or epidemic befell upon our prehistoric ancestors and if so, how did they manage to get rid of such disasters? From all accounts it appears that some diseases originated at that time still prove to be fatal or lethal for human beings. [ABSTRACT FROM AUTHOR]