Homosexual Orientation in Males: Evolutionary and Ethological Aspects

Evolutionary theory proposes that adaptive traits are reproduced more successfully than maladaptive traits. Accordingly, natural selection should favour heterosexuality as it facilitates reproduction and the propagation of genes. However, the question becomes, what has maintained homosexuality in a small but consistent percentage of the human population? Research into the evolutionary and hormonal factors associated with a homosexual orientation have yielded provocative but inconsistent results. It also suggests that human sexual orientation, and in particular homosexual orientation, is too complex to be described by one simple model or a single research discipline. The current paper treads a new path and emphasises an integrative approach for the understanding of homosexuality. The authors examine the combined effects of evolutionary factors and neurohormonal processes on the development of a homosexual orientation. It is suggested that research into the topic could benefit from an examination of and change in some of the assumptions upon which much past research has been based

Strain effects on the optical properties of lead-halide perovskites

In the last decade, lead-halide perovskites have gathered significant attention due to their fascinating optoelectronic properties which make them suitable for a plethora of applications (e.g. solar cells, light-emitting diodes, scintillators, thermoelectric devices, lasers). The versatility of these materials results from the possibility to tune their properties by directly manipulating their chemical composition and structure. To make full use of this tunability we need to be able to understand the relationship between structure and properties. Due to the strong connection between structural and optoelectronic properties, external pressure and, more in general, strain, can be used to manipulate the optical properties of these materials targeting specific device applications. Chapter 1 starts with an introduction to lead-halide perovskites and to their peculiar electronic structure highlighting how strain can affect the optical properties of such materials. Chapter 2 investigate two different fabrication methods of perovskite thin films. The fabrication results in different crystal growth. EBSD and spatially-resolved photoluminescence are used to correlate structural and optical properties of such films. Chapter 3 presents an investigation on the hot-carrier cooling process. We investigate how manipulating the lattice properties by applying external pressure affects the rate at which the hot electrons cool to the lattice temperature. Pressure has also an effect on the phase stability of mixed-halide perovskites, being an effective tool to manipulate the thermodynamics and kinetics of phase segregation as reported in Chapter 4. Finally, in Chapter 5 the structure-properties relationship in 2D perovskites is investigated

A Flexible Design Case Study: Leveraging Traits to Identify, Develop and Retain High-Potential Officers in the United States Air Force

This article details a single case study on the topic of identifying, developing, and retaining high-potential (HiPo) United States Air Force (USAF) officers. A model is proposed for organizations to better identify, develop and monitor, and retain HiPos. The case study conducted included 23 active or retired (less than 10 years) USAF colonels and general officers in the financial management career field as participants. Each participant was given a 20-question survey, a Big Five personality test, and an 11-question, hour-long interview. From the collected data, a total of six themes related to USAF HiPo management were discovered. Furthermore, the quantitative analysis that was conducted on the Big Five Personality Test result findings showed that statistically significant results were achieved. Specifically, the research found that the results for Openness to Experience, Conscientiousness, Agreeableness, and Neuroticism were statistically significant, while Extraversion was not. This article focuses on the findings regarding HiPo identification, the benefits of the practice, and how traits and trait theory can be related to leadership potential. The article also provides a Christian perspective on the business problem and the study’s findings

Role of Gut Microbiome in Rock Ptarmigan Health and Population Cycles

Research Poste

13. Long Term Care: Medicaid Reimbursement Does High Cost Yield High Quality?

This paper suggests a new focus for government policy in the providing of Medicaid services. To put it simply, the government needs to provide incentives (and sanctions) that make the business of caring for the elderly profitable to proprietary nursing home. Although profit and quality care are strange bedfellows, the government must adapt the Medicaid system to keeping them close (i.e., maintaining a positive relationship between profit and quality care)

Automatic Seeder

Our Senior Design Project is the construction and implementation of an automatic seeder that is to be used in the agricultural industry. The automatic seeder is being designed to eliminate prevalent issues within the process of planting seeds by hand, such as labor requirements and inconsistent operations. The seeder is meant to reduce time spent on planting seeds and place them in an efficient manner for optimal growth conditions. This project will require several specific research questions to be addressed in the form of application and good usability. We will investigate the method of planting the seed, the conveyor track for the apparatus to move on, and the overall time effectiveness of our device on the planting process. Through mathematical modeling and design embodiment we will address the correct application uses, such as the force required to plant the seed and the power input for the model. Our overall goal is to have our device provide an efficient and meaningful process of planting seeds for small farming establishments. By doing so, an easier accessible food source will be available to areas in need. An example of this is the agricultural process in India. In India’s current state, the agricultural industry for smaller size farms is mainly composed of human labor as a workforce. This has proven to be time costly and error abundant. The introduction of our Automatic Seeder will provide a new way to ration planting seeds at a consistent basis. The seeder will accommodate any potting tray and will insert seeds underneath the soil for each pot location on the tray. The seed being placed underneath the soil is a main goal of ours, as this is an active problem with the current hand labor methods. As opposed to the hand planting method, our seeder will be precise with the amount of seeds to be planted to help lower planting costs and to establish a stable base planting method. This seeder will help small businesses plan costs more efficiently for buying seeds, planting time, crop growth, and a predictable harvest

Tiger beetles of Sicily (Coleoptera Cicindelidae)

Tiger beetles (Coleoptera Cicindelidae) are predators, both in the larval and adult state and each species tends to be specialized within a narrow habitat. For this reason, tiger beetles are excellent indicators of the quality of the biotopes in which they live and of the possible degradation of said biotopes due to anthropic actions. Currently the populations of Cicindelidae are declining almost all over the world due to the destruction of the environments in which they live. In the Euro-Mediterranean area, including Italy, Cicindelidae mainly live in sandy environments like beaches, river mouths, the edges of lagoons and dune, and backdune ponds. Few species live on rocky coasts, in inland locations or in environments far from water such as paths and forest clearings. From what has been said, the coastal environments generally preferred by Cicindelidae are precisely those which in Italy, and also in Sicily, have undergone the greatest alteration and, often, destruction by man and his activities. In Sicily the Cicindelidae have always been studied since the first regional catalogs of the 19th century and other works were carried out in the following years, up to the present day. In the last decade, numerous reports have spread on the web, in numerous online chats, nature forums, etc. The aim of this work is to summarize and improve in a catalog what is known so far about the Sicilian Cicindelidae to highlight their peculiar systematic, ecological and geographical characteristics also in relation to the environment in which they live

Quantification of Ion Migration in CH3NH3PbI3 Perovskite Solar Cells by Transient Capacitance Measurements

Solar cells based on organic-inorganic metal halide perovskites show efficiencies close to highly-optimized silicon solar cells. However, ion migration in the perovskite films leads to device degradation and impedes large scale commercial applications. We use transient ion-drift measurements to quantify activation energy, diffusion coefficient, and concentration of mobile ions in methylammonium lead triiodide (MAPbI3) perovskite solar cells, and find that their properties change close to the tetragonal-to-orthorhombic phase transition temperature. We identify three migrating ion species which we attribute to the migration of iodide (I-) and methylammonium (MA+). We find that the concentration of mobile MA+ ions is one order of magnitude higher than the one of mobile I- ions, and that the diffusion coefficient of mobile MA+ ions is three orders of magnitude lower than the one for mobile I- ions. We furthermore observe that the activation energy of mobile I- ions (0.29 eV) is highly reproducible for different devices, while the activation energy of mobile MA+ depends strongly on device fabrication. This quantification of mobile ions in MAPbI3 will lead to a better understanding of ion migration and its role in operation and degradation of perovskite solar cells

Functional and Phylogenetic Dimensions of Tree Diversity Across Environmental Gradients in Puerto Rico: Insights to community assembly processes

One goal central to ecology is to understand how species interactions and biophysical processes interact over vastly different scales to govern past, current, and future patterns of diversity. Today, this goal is particularly critical given the degree to which rapid environmental change is affecting species distributions and community composition. Natural environmental gradients provide excellent opportunities to uncover possible mechanistic links between species distributions and environmental conditions links that are invaluable for understanding how species may respond to environmental change. This dissertation builds on recent approaches that combine information on species' functional traits and evolutionary histories to refine our view of how contemporary and historical processes jointly govern the distribution of biodiversity. In the context of tropical tree communities of Puerto Rico, the following four chapters evaluate hypotheses about the distribution of different dimensions of diversity (i.e., species, functional, and phylogenetic) across regional abiotic gradients. In chapter 1, I develop an island-wide molecular phylogeny for the native and naturalized trees of Puerto Rico, and show preliminary evidence that dry forests comprise an evolutionarily clustered subset of the total island tree flora. In chapter 2, I examine functional and phylogenetic diversity across spatial resource gradients, and use these patterns to infer variation in community assembly processes along a gradient of water availability. In chapter 3, I use temporal shifts of functional and phylogenetic diversity during secondary succession to infer the shifts in the processes underlying successional change in wet forests of Puerto Rico. Finally, in chapter 4, I evaluate the linkages between species functional traits and their geographic distributions, and test the hypothesis that community-weighted mean trait values reflect the `optimal' strategy for a given set of abiotic conditions. A theme common to all chapters is the idea that functional and phylogenetic dimensions of diversity can shed light on the processes underlying patterns of diversity better than more traditional metrics of species diversity. I provide recommendations for future research directions at the end of each chapter and in the final conclusions

Zeolites for the nutrient recovery from wastewater

To meet the growing food demand of the world population, excessive use of chemical fertilizers is occurring to improve soil fertility and crop production. The excessive use of chemical fertilizers is not economically and environmentally sustainable. Indeed, from one hand, due to the increasing demand of fertilizers is rising their costs whereas, on the other hand, the accumulation of fertilizers in wastewaters is altering the homeostasis of the ecosystems thus causing serious damages to human health [1,2]. The recovery of nutrients, such as nitrogen (N) and phosphorus (P), from wastewaters is a good option to counteract both economic and environmental issues raised by the excessive use of fertilizers [3]. Adsorption is among the most widely used methods for nutrient recovery from wastewaters due to its efficiency and simplicity. The choice of appropriate adsorbent materials is a key issue for ensuring high performance and low costs of the process [4]. Over the years, several materials have been studied to absorb nutrients from wastewaters. Zeolites, both natural and modified, have attracted great attention due to their relevant specific capacity, selectivity, safety, and stability [5]. However, considering that in municipal effluents the inorganic P exists as the anionic forms of dihydrogen or monohydrogen phosphates (H2PO4 − and HPO42−, respectively) and N in both cationic (ammonium, NH4+) and anionic (nitrate, NO3−) form [6], natural zeolites can be only used for the direct recovery of NH4+