Silicon Waveguides and Ring Resonators at 5.5 {\mu}m

We demonstrate low loss ridge waveguides and the first ring resonators for the mid-infrared, for wavelengths ranging from 5.4 to 5.6 {\mu}m. Structures were fabricated using electron-beam lithography on the silicon-on-sapphire material system. Waveguide losses of 4.0 +/- 0.7 dB/cm are achieved, as well as Q-values of 3.0 k.Comment: 4 pages, 4 figures, includes supplemental material

DNA Sampling: a method for probing protein binding at specific loci on bacterial chromosomes

We describe a protocol, DNA sampling, for the rapid isolation of specific segments of DNA, together with bound proteins, from Escherichia coli K-12. The DNA to be sampled is generated as a discrete fragment within cells by the yeast I-SceI meganuclease, and is purified using FLAG-tagged LacI repressor and beads carrying anti-FLAG antibody. We illustrate the method by investigating the proteins bound to the colicin K gene regulatory region, either before or after induction of the colicin K gene promoter

Effects of grass species and grass growth on atmospheric nitrogen deposition to a bog ecosystem surrounded by intensive agricultural land use

We applied a N-15 dilution technique called Integrated Total Nitrogen Input (ITNI) to quantify annual atmospheric N input into a peatland surrounded by intensive agricultural practices over a 2-year period. Grass species and grass growth effects on atmospheric N deposition were investigated using Lolium multiflorum and Eriophorum vaginatum and different levels of added N resulting in increased biomass production. Plant biomass production was positively correlated with atmospheric N uptake (up to 102.7mg N pot(-1)) when using Lolium multiflorum. In contrast, atmospheric N deposition to Eriophorum vaginatum did not show a clear dependency to produced biomass and ranged from 81.9 to 138.2mgNpot(-1). Both species revealed a relationship between atmospheric N input and total biomass N contents. Airborne N deposition varied from about 24 to 55kgNha(-1)yr(-1). Partitioning of airborne N within the monitor system differed such that most of the deposited N was found in roots of Eriophorum vaginatum while the highest share was allocated in aboveground biomass of Lolium multiflorum. Compared to other approaches determining atmospheric N deposition, ITNI showed highest airborne N input and an up to fivefold exceedance of the ecosystem-specific critical load of 5-10kgNha(-1)yr(-1).Peer reviewe

Role of Computed Tomography in Traumatic Brain Injuries

This project explains the role of computed tomography (CT) in assessing traumatic brain injuries (TBI). The major components of the research include various intracranial traumas, penetrating vs. non-penetrating TBIs, symptoms, grades of injury, and treatment options. CT is essential in diagnosing a TBI because it can quickly produce hundreds of images of the brain and skull in slices. CT allows radiologists, physicians, and surgeons to plan a course of action for the best possible patient recovery outcome. Images can identify various lesions and fractures as well as their severity. A TBI can present itself as penetrating or non-penetrating, ultimately determining the type of treatment the patient will receive. The symptoms of a TBI will differ depending on whether the injury is mild, moderate, or severe. Depending on how severe the injury is, a patient may require open or closed brain surgery to remove the damaged brain matter caused by the injury. Overall, a CT scan of the brain for patients who suffered a TBI allows healthcare professionals to determine what can be done to ensure the best outcome for recovery.https://digitalcommons.misericordia.edu/medimg_seniorposters/1059/thumbnail.jp

Identity in the Archaeological Record: Richardville, Natoequah and the Fur Trade in Northeastern Indiana.

Gender, ethnicity and social class are powerful structuring components that influence the formation of personal identity and social groups, as well as constrain interpersonal interactions within social groups. The following dissertation is an examination of how gender, ethnicity and class were actively negotiated and employed by Native Americans, Métis and whites to construct personal and social identities on the frontier during the nineteenth century fur trade. This discussion of identity will focus on the example of John B. Richardville to examine how he used material culture to construct, portray and maintain multiple personal and social identities in the nineteenth century fur trade. John B. Richardville served as the last civil chief of the Miami tribe (1816 - 1841) and it is argued that he actively drew upon elements of his ethnicity, gender, and class, while purposely utilizing material culture to create multiple social and personal identities. These identities were then strategically employed in different arenas of his life in order to secure his role within the Miami tribe, as well as within the dominant white, Euroamerican culture of the nineteenth century. A materialist approach framed within a gendered and identity based theoretical framework will be applied to the archaeological assemblages recovered from the Chief Richardville House (12AL1887) and the Chief Richardville House and Miami Treaty Grounds (12HU1013), as well as the structures themselves in order to examine how Richardville utilized material culture to accomplish these goals. It is hypothesized that Richardville actively portrayed different identities at each structure, utilizing different types of material culture to do so, creating unique archaeological signatures at each location. An analysis of these archaeological signatures and materials recovered from these sites is expected to illustrate the different facets of Richardville’s social and personal identity presented in each location

An Overview of Variation in Archaeologically Observed Mortuary Practices: A Case Study Examining Grave Placement, Headstone Type and Epitaph Content in Two Slave Cemeteries

Numerous explanations for archaeologically observed variation in the treatment of the dead have been posited by archaeologists, including but not limited to differentiation in rank, social organization, philosophical-religious beliefs and the rise and fall of social trends. The focus of this study is to explore the variation of headstones, their epitaphs and the arrangement of graves within two different cemeteries in the antebellum United States after reviewing the theory concerning variation in the archaeological record. The dialectical contrast of these variables between the Common Burying Ground cemetery in Newport, Rhode Island and a slave cemetery in New Orleans, Louisiana will demonstrate that both social organization and religious beliefs can be driving factors influencing the treatment of the dead

Bridging the Mid-Infrared-to-Telecom Gap with Silicon Nanophotonic Spectral Translation

Expanding far beyond traditional applications in optical interconnects at telecommunications wavelengths, the silicon nanophotonic integrated circuit platform has recently proven its merits for working with mid-infrared (mid-IR) optical signals in the 2-8 {\mu}m range. Mid-IR integrated optical systems are capable of addressing applications including industrial process and environmental monitoring, threat detection, medical diagnostics, and free-space communication. Rapid progress has led to the demonstration of various silicon components designed for the on-chip processing of mid-IR signals, including waveguides, vertical grating couplers, microcavities, and electrooptic modulators. Even so, a notable obstacle to the continued advancement of chip-scale systems is imposed by the narrow-bandgap semiconductors, such as InSb and HgCdTe, traditionally used to convert mid-IR photons to electrical currents. The cryogenic or multi-stage thermo-electric cooling required to suppress dark current noise, exponentially dependent upon the ratio Eg/kT, can limit the development of small, low-power, and low-cost integrated optical systems for the mid-IR. However, if the mid-IR optical signal could be spectrally translated to shorter wavelengths, for example within the near-infrared telecom band, photodetectors using wider bandgap semiconductors such as InGaAs or Ge could be used to eliminate prohibitive cooling requirements. Moreover, telecom band detectors typically perform with higher detectivity and faster response times when compared with their mid-IR counterparts. Here we address these challenges with a silicon-integrated approach to spectral translation, by employing efficient four-wave mixing (FWM) and large optical parametric gain in silicon nanophotonic wires

It\u27s All Greek to Me: Classical Influences on Georgian and Federal Architectural Styles in the American Colonies

When the British established colonies in North America, they brought with them their cultural practices and ideals, which can be seen in the architectural styles present in the New World. It is generally accepted that both the Early Colonial and Georgian styles were brought to North America through English influence over the colonies, however, architects are in disagreement as to whether the Federal style should be given its own designation. In order to understand the genesis of the stylistic influences behind both the Georgian and Federal styles in colonial and post-colonial North America, this paper will outline the characteristics of domestic structures that exemplify each style as well as the prominent architects associated with them. I will argue that the Federal style is a separate and distinct style from the Georgian style in post-colonial America due not only to variation of architectural and stylistic elements, but more importantly due to the social milieu of the period in which it arose

Looking for Hope: The Experience of Early Career Teachers Engaged in a Collaborative Community of Reflective Practice as a Model of Induction and Professional Development

Teaching has always been an isolated profession and many professional development programs are seen as disconnected from the realities and daily needs of teaching. With the pressures of standards, paperwork, classroom management, and learning to teach, early career teachers can be especially vulnerable to becoming discouraged, disillusioned, and demoralized. This study used a qualitative, narrative inquiry approach to tell the stories of seven early career teachers’ experiences with induction and the development of a reflective community to support early career teachers in their professional practice. As part of the action research approach taken in designing the program, the discussions and themes that emerged in the reflective community played a role in shaping the focus of the group and future discussions. By telling these stories and designing a model of induction and professional development based on reflection and collaboration, this study aimed to find and sustain hope in teachers’ situations through improving their practice and building community. The study revealed the importance of strong and supportive relationships with both peers and students and the benefit of the safe space and support found in a community of peers through discussing shared experiences and hearing new perspectives. The participants’ focus on relationships and community became especially critical in the context of navigating the interruptions and uncertainties brought about by the COVID-19 pandemic during the 2019-2020 school year

Perturbative and Ab-Initio Calculations of Electrical Susceptibilities of Atoms

Perturbative nonlinear optics consists of many powerful predictive theoretical methods, in- cluding the perturbative series of observables related to the interaction of light with matter. The light intensity limits of such series have been studied in the past for highly nonlinear processes such as above threshold ionization and high harmonic generation. A more recent debate focuses on the limits of applicability of perturbation theory for the nonlinear electrical susceptibility and the nonlinear index of refraction of atoms, which are important parameters to study, for example, for filamentation of laser pulses in nonlinear media.In this thesis we analyze theoretical predictions for the electrical susceptibility of atoms for the transition from the perturbative to the nonperturbative intensity regime. To this end, we apply a numerical basis state method that allows us to perform respective calculations in the framework of perturbation theory as well as using ab-initio methods. The results let us identify the intensity at which the application of perturbation theory breaks down. Furthermore, we provide an analysis of the nonlinear susceptibility as a function of time during the interaction with the laser pulse and find that theoretical predictions are in good agreement with recent experimental data