Coupling Avicennia tree architecture to radar backscatter models for estimating mangrove forest biomass

The understanding of mangrove ecosystems functioning requires techniques allowing their forest structure and forest biomass to be assessed. Among them, radar measurements have demonstrated powerful capabilities that, however, must be validated extensively, both spatially and physically. Beyond their intrinsic potential to provide basic information on tree growth and forest functioning, 3D tree architecture studies could help the interpretation of radar signal scattering within forest canopies to be performed and thus, improve the accuracy of radar inversion algorithms for estimating forest parameters such as total above-ground biomass and component biomass. Topological measurements have been conducted at different growth stages on Avicennia germinans trees with height less than 5 meters. For each tree measured, leaf size, nodes length and diameter are coded using the AMAPmod terminology. Thanks to this software and assuming stands composed of identical trees, input parameters for the radar backscatter models of forests are then derived from architectural analysis. The simulated radar responses are compared to radar measurements when available. The effect of tree architecture and the structure of associated stands are discussed with the objectives to estimate forest parameters using radar data. This work comes within the international project ALOS Kyoto and Carbon Initiative aiming to monitor forest dynamics, particularly mangrove forests. (Texte intégral

Methanation of CO over Ni catalyst: A theoretical study

Theoretical methods (generalized valence‐bond calculations) were used to examine the bond energies and geometries of numerous species chemisorbed onto Ni clusters representing Ni surface. These results were used to obtain thermochemical information and to examine various mechanisms for the methanation of CO over Ni: CO+3H^(→)_(2(Ni)) CH_4+H_2O. It is found that chemisorbed formyl radicals (Ni–CHO) lead to a favorably appearing chain reaction that is consistent with current experimental results. In addition, we find a chemisorbed C_2 species that may be the catalytically active C_(ad) formed from dissociation of CO

Ab initio effective potentials for use in molecular quantum mechanics

We have investigated the method of effective potentials for replacing the core electrons in molecular calculations. The effective potential has been formulated in a way which simplifies computations while producing wave functions of ab initio quality. The effective potential is expressed in an analytic form which (i) represents the actual ab initio nonlocal potential (as defined by the matrix elements for a given basis set) and (ii) permits efficient computations of the effective-potential integrals (by incorporating the properties of Gaussian basis functions). To minimize the number of basis functions required in the molecular calculations, we define a new ab initio effective potential derived from modified Hartree-Fock valence orbitals whose core character has been removed. The effective-potential method as formulated becomes a very strong and reliable tool in attempting calculations on very large molecules. Applications to Li, Na, and K are presented

Theoretical studies of nickel clusters and chemisorption of hydrogen

First principles calculations of high- and low-symmetry clusters (up to Ni87) are reported. Macroscopic properties [ionization potential (IP), electron affinity (EA), and bandwidth] are not sensitive to cluster symmetry and, except for EA, are converged to bulk values by Ni87. Even for Ni87 the EA is over 2.5 eV smaller than the IP; the origin of this effect is discussed. The chemisorption of hydrogen is considered on the low-symmetry clusters, where it is found that threefold and fourfold sites are most favored with bond energies of [angle]3 eV for both types of sites. Geometries are not cluster sensitive with R (NiH) values of 1.57, 1.62, and 1.78 Å for twofold, threefold, and fourfold sites, respectively. Vibrational frequencies for these sites are 1420, 1212, and 592 cm^–1, respectively

Understanding Saudi Student Integration in the U.S.: A Study on Saudi Students at a Southeastern Institution

Over the past decade there has been an increase in the number of Saudi students studying in the United States. Most recently, Saudi Arabia moved from fourth to third in country ranking for student enrollment in the United States. This study focuses on the experiences of Saudi students at a Southeastern institution in the United States by examining the perspectives of Saudi students studying in English as a Second Language (ESL) programs and undergraduate programs. In order to gain a deeper understanding of issues faced by Saudi students, domestic students as well as instructors were also included as participants in this study. Mezirow’s (1996) transformative learning theory and Barker’s (1981) neo-racism theory were incorporated into the theoretical framework of this research. Through in-depth interviews, there were five emerging themes present, including: religion, appearance/clothing, language, media, and culture

Effects of Atrazine on Penned Pheasants and the Occurrence of Stress Marks on Feathers

Doses of 4 g of atrazine (AAtrex) were not lethal to penned hen pheasants (Phasispus colchicus), but levels of 6, 8, 10 and 12 g induced mortality. Pen studies to determine the effects of atrazine on reproduction of hen pheasants were conducted with two replicates of the basic test. Birds were administered treatment levels of 0, 100, 200, or 400 mg of atrazine per hen per week. Egg production and gain in weight of hens were unaffected by the treatments. Replicate A eggs were unaffected by the treatments. Replicate A eggs were unaffected in shell thickness and pipping rates, while fertility and hatchability were statistically different. Replicate B eggs were unaffected in fertility, hatchability and shell thickness but indicated a significant difference in pipping rates. Hens receiving 200 and 400 mg of atrazine laid eggs that were significantly lighter in weight than eggs from control birds. Survival and gain in weight of chicks were not different between treatments. Effects of the atrazine on behavior tested with visual cliff performance and susceptibility to hand capture indicated no differences between experimental and control birds. Stress marks were visible in plumage of pheasants subjected to environmental change, limited diet, and caging. Stress marks related to atrazine ingestion were not determinable in the experimental design utilized

The Effects of Reading Strategies on EL Students while Transitioning into a Middle School Mainstream ELA Setting

The purpose of this action research was to determine if specific reading strategies would successfully support English Language Learners (ELLs) as they transitioned from an English Learning classroom setting into a mainstream English-Language Arts classroom. The research took place over an approximately six-month period in a public middle school in central Minnesota during a mix of hybrid and distance learning as a result of the COVID-19 pandemic. The focus population included six seventh-grade ELLs. Data collection took place through quantitative and qualitative measures, including Google Form surveys, formative and summative assessments, writing diagnostics and final essays. The changes to the learning environment led to inconsistent data collection and student participation. Continued research is needed to determine the overall effectiveness of the learning strategies on the ELL student population

The Lived Experience of Vicarious Trauma for Providers: A Narrative Phenomenoleogical Study

This research seeks to gain a greater understanding of the first-hand, lived experience of vicarious trauma for providers who have worked with individuals experiencing trauma. Through the application of phenomenological and participatory action methodologies, the experience of vicarious trauma is illuminated. Narrative exchanges between the co-researchers–the author and eleven providers–further explore the roles of the body and narrative process within this phenomenon. A conceptual evolution of vicarious trauma is presented, along with literature connecting the body and narrative within the trauma field. Data includes co-researcher’s recorded and transcribed interviews, vicarious trauma narratives, and written feedback. Embodied writing selections conducted by the author serve as an additional form of data, capturing the nuanced, embodied data within the narrative process. Using narrative analysis, the major verbal and non-verbal themes of vicarious trauma are identified for the co-researchers involved in this study. Findings offer directions for future research into the phenomenon of vicarious trauma, as well as future suggestions for the development and application of body-based and dance/movement therapy techniques to address the impacts of vicarious trauma for providers working with the trauma field

Trolling for Standards: How Courts and the Administrative State Can Help Deter Patent Holdup and Promote Innovation

Antitrust law and patent law share the common goal of improving economic welfare by facilitating competition and innovation. But these legal fields conflict when baseless claims of patent infringement disrupt the competitive process. In its eBay decision, the Supreme Court muddied the precedential waters by promulgating a vague doctrine of injunctive relief in patent infringement cases. In the years since, a split has emerged in the district courts on the question of which entities generally qualify for injunctive relief as an additional remedy to damages. This uncertainty has failed to mitigate an antitrust phenomenon known as patent holdup, whereby an original patentee is able to hold up a downstream user of a particular patent by obtaining or threatening to seek an injunction in order to extract a supracompetitive royalty payment from the downstream licensee. The phenomenon implicates antitrust law when such litigation tactics, often pursued by patent-assertion entities (PAEs or patent trolls\u27), produce deadweight loss, chill follow-on innovation, and reduce competition. Courts have generally not taken holdup considerations into account in applying the vague eBay standard, and they lack the economic expertise to do so properly. Guidance is needed from a specialized administrative agency that is sensitive to the nuances of both patent and antitrust law. This Note proposes that Congress give the Federal Trade Commission authority to promulgate substantive rules to guide the district courts in their application of permanent injunctions in patent disputes