Showing papers by "Louisiana State University published in 2023"

Proactive and reactive aggression: Developmental trajectories and longitudinal associations with callous–unemotional traits, impulsivity, and internalizing emotions

Abstract: Research on proactive and reactive aggression has identified covariates unique to each function of aggression, but hypothesized correlates have often not been tested with consideration of developmental changes in or the overlap between the types of aggression. The present study examines the unique developmental trajectories of proactive and reactive aggression over adolescence and young adulthood and tests these trajectories' associations with key covariates: callous-unemotional (CU) traits, impulsivity, and internalizing emotions. In a sample of 1,211 justice-involved males (ages 15-22), quadratic growth models (i.e., intercepts, linear slopes, and quadratic slopes) of each type of aggression were regressed onto quadratic growth models of the covariates while controlling for the other type of aggression. After accounting for the level of reactive aggression, the level of proactive aggression was predicted by the level of CU traits. However, change in proactive aggression over time was not related to the change in any covariates. After accounting for proactive aggression, reactive aggression was predicted by impulsivity, both at the initial level and in change over time. Results support that proactive and reactive aggression are unique constructs with separate developmental trajectories and distinct covariates.

Optimizing the Self-Healing Efficiency of Hydrogel-Encapsulated Bacteria in Concrete

Abstract: The main objective of this study is to evaluate and optimize the crack healing efficiency of hydrogel-encapsulated bacteria in concrete applications. To achieve this objective, Bacillus pseudofirmus was evaluated as the bacteria strain, which was combined with three mineral precursors corresponding to magnesium acetate, calcium lactate, and sodium lactate at two concentrations (67.76 and 75 mM/L). For each combination, three sets of mortar cubes, along with three sets of mortar beams, were prepared. The mechanical properties of these specimens were characterized by compressive and flexural strength tests. Once the beams were cracked, they were subjected to 28 days of wet/dry cycles in which crack width was monitored. Once the wet/dry cycles were completed, the specimens were retested to determine the strength recovery. In the compressive strength and self-healing efficiency tests, mortar samples prepared with calcium lactate at a concentration of 75 mM/L along with bacteria and yeast extract showed the best performance. With respect to flexural strength recovery, no significant difference was noted among the specimens. Microscopic evaluation revealed a high concentration of calcium-rich crystals (i.e., calcium carbonate or calcium hydroxide crystals) indicative of bacterial activities. A scale-up concrete study was performed based on the best-performing mortar samples and then compared to plain concrete. Results from the concrete analysis indicated that the addition of calcium lactate improved concrete’s flexural strength. However, the plain concrete control specimen displayed superior healing efficiency after being subjected to wet/dry cycles.

Molecular characteristics of periodontal health: Collagens

Abstract: Background Defining periodontal health has been an ambitious and complex goal. The numerous and varied definitions of what constitutes periodontal health have resulted in a collection of subjective and unreliable clinical findings to diagnose and classify periodontal health and disease. The aim of this study was to fundamentally delineate the molecular characteristics of healthy periodontal tissues in men and women as they age, using the most abundant connective tissue component: Collagens. Methods Healthy gingival biopsies were separated into “young” (aged 18–35 years, five men/five women) and “old” (≥60 years, five men/four women) age groups depending on biological sex. RNA was extracted and next-generation RNA sequencing was performed using Unique Molecular Identifiers. Collagen gene expression was determined and quantified for young and old, male and female individuals. Results Twenty-six human collagens were identified in healthy gingival tissues. In general, age and biological sex affected expression of collagen α-chain transcripts. Ten of the 26 human gingival collagen genes formed a unique pattern for gingival health. More specifically, the expression of fibrillary (types I and III), fibril-associated collagens with interrupted triple-helices (FACIT) and FACIT-like (types XII, XIV, and XX), network-forming (types IV and VI), transmembrane (type XVII), and multiplexin (types XV and XVIII) collagens, taken together, exhibited a distinct pattern of characteristics for gingival health that was independent of age or biological sex. Conclusions Although specific α-chains of the collagen transcriptome were affected by age and biological sex, the compilation of various collagen transcripts can be used to define gingival health that is independent of age and biological sex.

Effects of alloying elements on diamond/Cu interface properties based on first-principles calculations

Abstract: Diamond/copper composites with high thermal conductivity and a variable thermal expansion coefficient are promising materials for thermal management applications. However, achieving the desired thermal conductivity of the composite material is difficult due to detachment or weak bonding between diamond and Cu. The interfacial properties of diamond/Cu composites can be improved using metal matrix alloying methods. In this study, we investigate the effects of alloying elements (B, Cr, Hf, Mo, Nb, Si, Ti, V, Zr) on the interfacial properties of diamond/Cu using first-principles calculations. Results showed that all alloying components could increase the interfacial bonding of diamond/Cu. Analysis of the electronic structure revealed that increased interfacial bonding strength after doping was the result of the stronger bonding of the alloying element atoms to the C atoms. The C atoms in the first layer of diamond at the interface formed wave peaks near the Fermi energy level after doping with B or Si atoms, facilitating electron-phonon interaction at the interface. The phonon properties of B4C and SiC were similar to those of diamond, which facilitated phonon-phonon coupling. B and Si were shown to be better alloying elements when interfacial bond strength and heat transfer were considered.

Pursuing Change or Pursuing Credit? Litigation and Credit Claiming on Social Media

Abstract: Abstract Interest groups often post about their judicial advocacy on social media. We argue that they do so for two main reasons. First, providing information about the courts on social media builds the group’s credibility as a source of information with policymakers, media and the public. Second, social media provides a way to claim credit for litigation activity and outcomes, which can increase membership and aid in fundraising. Using original datasets of millions of tweets and Facebook posts by interest groups, we provide evidence that interest groups use social media for public education and to credit claim for their litigation activity.

Quantum Gravitational Non-Singular Tunneling Wavefunction Proposal

Abstract: It was recently shown that tunneling wavefunction proposal is consistent with loop quantum geometry corrections including both holonomy and inverse scale factor corrections in the gravitational part of a spatially closed isotropic model with a positive cosmological constant. However, in presence of an inflationary potential the initial singularity is kinetic dominated and the effective minisuperspace potential again diverges at zero scale factor. Since the wavefunction in loop quantum cosmology cannot increase towards the zero scale factor, the tunneling wavefunction seems incompatible. We show that consistently including inverse scale factor modifications in scalar field Hamiltonian changes the effective potential into a barrier potential allowing the tunneling proposal. We also discuss a potential quantum instability of the cyclic universe resulting from tunneling.

A review of geographic information system (GIS) and techno economic (TE) software tools for renewable energy and methodology to develop a coupled GIS-TE software tool for marine renewable energy (MRE)

Abstract: Accurate and up-to-date Geographic Information System (GIS) and Techno Economic (TE) tools are pertinent to helping to develop the renewable energy sector. This paper reviews the state of the art in existing GIS and TE tools for renewable energy and proposes a methodology to develop a coupled GIS-TE software tool that is geared specifically to Marine Renewable Energy (MRE) applications and bespoke to Irish and Western UK waters. Methods for approaching GIS and TE analysis within existing tools for renewable energy are presented and compared. Many existing tools of this nature have some interesting functionalities, but most are unsuitable for MRE; are limited by a lack of information on both the technology and the site; and focus solely either on GIS or TE aspects of analysis. Additionally, almost all of those with a TE focus are not open access. The proposed tool aims to incorporate increased resolution and site relevance of resource data; the most up-to-date geospatial data for site selection; and will provide site specific TE indicators and recommendations for contemporary MRE devices. The result will be the development an open-access GIS-TE software tool for MRE.

Drilling, Completion, and Monitoring Operations

Abstract: Drilling and completion of shale wells have a profound influence on well performance and associated reserves. Before introduction of massive fracturing of horizontal wells, it was not technically and economically feasible to produce most shale resources implying reserves were essentially zero. Optimizing the drilling and completion operations requires close monitoring of the operation with the aim of improving it. Different monitoring strategies must be adopted to ensure the stimulation fluids are directed to maximize the efficiency of fracturing operation. In this chapter, drilling, completions, and monitoring operations are introduced. By the end of this chapter, the reader will be able to: (1) describe how well drilling in shale/tight reservoirs differs from the conventional drilling considering well pads, well direction, and zonal isolation. (2) explain the operation of multiple fracturing (and re-fracturing) of horizontal wells and the required equipment, fluids, and proppant. And (3) discuss the methods applied to diagnose the success of hydraulic fracturing treatment using temperature, acoustic, and strain monitoring.

Molecular Research in Rice

Abstract: Rice is the most important source of nutrition for approximately half of the human population [...].

Cultural Patterns of Colored Creoles: A Study of a Selected Segment of New Orleans Negroes With French Cultural Orientations

Abstract: This thesis is a study of the cultural patterns of Negroes, roughly of the middle and upper classes, of French background in New Orleans, Louisiana. Both primary and secondary materials were utilized in the study. The principal sources of data used were interviews, informal conversations, and secondary materials.

<scp>DeepBryo</scp>: A web app for <scp>AI</scp>‐assisted morphometric characterization of cheilostome bryozoans

Abstract: Bryozoans are becoming an increasingly popular study system in macroevolutionary, ecological, and paleobiological research. Members of this colonial invertebrate phylum display an exceptional degree of division of labor in the form of specialized modules, which allows for the inference of individual allocation of resources to reproduction, defense, and growth using simple morphometric tools. However, morphometric characterizations of bryozoans are notoriously labored. Here, we introduce DeepBryo, a web application for deep-learning-based morphometric characterization of cheilostome bryozoans. DeepBryo is capable of detecting objects belonging to six classes and outputting 14 morphological shape measurements for each object. The users can visualize the predictions, check for errors, and directly filter model outputs on the web browser. DeepBryo was trained and validated on a total of 72,412 structures in six different object classes from images of 109 different families of cheilostome bryozoans. The model shows high (> 0.8) recall and precision for zooid-level structures. Its misclassification rate is low (~ 4%) and largely concentrated in two object classes. The model's estimated structure-level area, height, and width measurements are statistically indistinguishable from those obtained via manual annotation. DeepBryo reduces the person-hours required for characterizing individual colonies to less than 1% of the time required for manual annotation. Our results indicate that DeepBryo enables cost-, labor,- and time-efficient morphometric characterization of cheilostome bryozoans. DeepBryo can greatly increase the scale of macroevolutionary, ecological, taxonomic, and paleobiological analyses, as well as the accessibility of deep-learning tools for this emerging model system.

School-Based Interventions for Students with Autism

Abstract: The prevalence of autism has increased year over year over the past several decades. The continued increase in rates of diagnosis has prompted various changes to models of service prior to, during, and following the school-age years. At present, most behavior analytic research with autistic children has focused on intervention during the preschool age range under the broader label of Early and Intensive Behavioral Intervention (EIBI) and less research has focused on school-based support provided throughout the school-age years. This chapter provides a review of various school-based supports for school-aged autistic children as well as provides a review of the school-based systems that applied behavior analysts often operate within. A discussion of the diagnostic label of autism is presented to highlight the differences between determining eligibility for support in clinical and educational settings. Various interventions are discussed, special education law and policies are reviewed, and suggestions for behavior analysts supporting autistic learners within school systems are provided. Suggestions for current and future behavior analysts planning to work in school systems are also presented.

Thermoset polymer composites with gradient natural and synthetic fiber reinforcement: Self-healing, shape-memory, and fiber recyclability

Abstract: Natural fibers have high potential as renewable reinforcement for polymers; however, their lower load-carrying capacity compared to synthetic fibers significantly limits the wide application in fiber-reinforced polymer composites. In laminated composite beams under bending load, the normal stress is the highest on the top and bottom layers but is zero at the mid-plane, with almost a linear normal strain distribution. Although the shear stress is the highest at the mid-plane, it may not be a major concern as most polymers can survive the high shear stress. Using this concept, we have designed a hybrid fiber reinforcement in a gradient manner: from the surface to the mid-plane were carbon fiber, glass fiber, and natural jute fiber, respectively. A newly synthesized self-healable shape memory polymer was used for laminating the fibers. Performance characterizations demonstrated that even using a significant amount of natural fibers in the composites, the samples with gradient fiber reinforcement showed competitive mechanical properties to fully carbon or glass fiber reinforced composites and much higher mechanical properties than the composite prepared with entirely natural fibers or glass fibers. For example, the gradient composites show up to 550 % flexural strength of the composites made of fully natural fibers, and around 14 % and 34 % higher flexural strength than that of the composites made of pure glass and pure carbon fibers, respectively. In addition, the composites retain excellent self-healing, shape-recovery, and fiber-recycling properties.

Reserve Estimation Through Rate-Time Analysis

Abstract: In this chapter and the next, the methods for hydrocarbon reserve estimation of shale resources are covered. In this chapter, we first review the basic definitions relevant to resources and reserves, and the available methods for their evaluation. The importance of rate-time analysis techniques (e.g. Arps’ decline curve analysis) to estimate shale reserves is discussed. Next, we introduce and apply the most commonly used rate-time analysis methods in shale reserve estimation including, Arps’ (exponential, hyperbolic, and harmonic), Stretched exponential, Power law exponential, Duong, and Logistic growth.

“The Hidden Figure of a Global Crime”: From Human Trafficking to Human Rights: Complexities and Pitfalls

Abstract: According to the International Labor Organization (ILO), between 20 and 40 million individuals are victims of trafficking in persons, also known as modern slavery. This chapter has five goals. The first goal is to discuss the recruitment of individuals into modern slavery. The second goal is to examine the risk factors associated with modern slavery. The third goal is to discuss the fate of African slaves, drawing several parallels to the Transatlantic Slave Trade and modern slavery. The fourth goal is to compare historical and modern slavery. The final goal is to examine the strides that policy, the law, and mental health professionals have made to help eradicate modern slavery and help victims of human trafficking to successfully integrate into society.

Death, Doubt, and Poe’s Global Ascendancy

Abstract: Poe’s contemporary appeal derives ultimately from his recognition of two phenomena: (1) the rise of radical skepticism as science undermined religious belief; and (2) the emergence, via mass media, of a “culture of fear” focused on dire threats. Modern death anxiety dates, surprisingly, from the Enlightenment, provoked partly by medical dissection of cadavers. Efforts to pinpoint causes of mortality revealed cases of “uncertain death” and excited fear of premature burial—Poe’s trope for quintessential dread. He embedded theological doubt in works such as “Ligeia,” “The Raven,” and Eureka. Ligeia’s protest to God, the speaker’s perverse questions to the raven, and Poe’s elision of decay in Eureka all reveal the challenge of reconciling death with eternal life. Catechized in Anglicanism, Poe both flaunted and resisted despair. He perceived the fixation of mass culture upon death, especially atrocities of the Rue Morgue variety. In “The Conversation of Eiros and Charmion,” “The Masque of the Red Death,” and “Hop-Frog,” he anticipated global destruction, worldwide pestilence, and terrorism, respectively. But he also conceived comic and serious fables of survival—from “A Predicament” to “The Pit and the Pendulum.” His work resonates with readers everywhere because it brilliantly captures our modern, existential plight.

Short Communication: Motivation for standardizing and normalizing inter-model comparison of computational landscape evolution models

Abstract: Abstract. This manuscript is a call to the landscape evolution modeling community to develop benchmarks for model comparison. We illustrate the use of benchmarks in illuminating the strengths and weaknesses of different landscape evolution models (LEMs) that use the stream power process equation (SPPE) to evolve fluvial landscapes. Our examples compare three different modeling environments—CHILD, Landlab, and TTLEM—that apply three different numerical algorithms on three different grid types. We present different methods for comparing the morphology of steady-state and transient landscapes, as well as the time to steady state. We illustrate the impact of time step on model behavior. There are numerous scenarios and model variables that we do not explore, such as model sensitivity to grid resolution and boundary conditions, or processes beyond fluvial incision as modeled by the SPPE. Our examples are not meant to be exhaustive. Rather, they illustrate a subset of best practices and practices that should be avoided. We argue that all LEMs should be tested in systematic ways that illustrate the domain of applicability for each model. A community effort beyond this study is required to develop model scenarios and benchmarks across different types of LEMs.

Definitions, History, and Differentiating Characteristics of Shale Hydrocarbon Recovery

Abstract: In this chapter, the meaning of the term “shale” as a hydrocarbon resource is described. Next, a brief history of shale hydrocarbon recovery is presented and major steps taken to unlock its significant potential are discussed. As discussed in details in this chapter, most shale reservoirs are petroleum source rocks. The implications of the source rock nature of shale reservoirs for hydrocarbon accumulation and reservoir development is covered by explaining (1) the origin of oil and gas, (2) relative amounts and distribution of source rock resources as compared to conventional reservoirs, and (3) parameters controlling the source rock quality primarily based on the form of containing organic matter and rock pore space. The major learning outcomes of this chapter are therefore: (1) Define the term “shale” in shale hydrocarbon recovery, (2) describe the technological evolutions that led to unlocking shale recovery in the US, and (3) identify the implications of the shale as a source rock for its hydrocarbons content and type, areal extent, and recovery approach.

End block Dynamics in Unentangled Polymers by Dielectric Spectroscopy

Abstract: Dielectric spectroscopy measures the dynamics of polymer melts over a broad frequency range. Developing a theory for the spectral shape can extend the analysis of dielectric spectra beyond determining relaxation times from the peak maxima and adds physical meaning to shape parameters determined with empirical fit functions. Toward this goal, we use the experimental results on unentangled poly(isoprene), and unentangled poly(butylene oxide), polymer melts, to test whether the concept of end blocks could be one reason for the Rouse model deviating from experimental data. These end blocks have been suggested by simulations and neutron spin echo spectroscopy and are a consequence of the monomeric friction coefficient depending on the position of the bead in the chain. The concept of an end block is an approximation which partitions the chain in a middle and two end blocks to avoid overparameterization by a continuous position dependent change of the friction parameter. Analysis of dielectric spectra shows that the deviations of the calculated from the experimental normal mode cannot be related to the end block relaxation. However, the results do not contradict an end block hiding below the segmental relaxation peak. It seems that the results are compatible with an end block being the specific part of the sub-Rouse chain interpretation close to the chain ends.