Design and Optimization of an Ionizing-Radiation-Free Dental Imaging Scheme by Near Infrared Fluorescence

There is a global need for access to oral health care. Proper oral health care is necessary for physiological and psychological health, as well as social and economic issues. Major oral diseases that must be screened include caries, cracked teeth, and impacted molars. These diseases are screened and diagnosed using a variety of medical imaging methods, computed tomography (CT) X-ray being the most popular and efficient method. The challenges in screening with X-ray technology include financial and time cost as well as health risk, including radiation exposure induced cancer (REIC). This thesis summarizes research to explore the possibility of overcoming these challenges using indocyanine green (ICG) near infrared (NIR) fluorescent imaging. An NIR imaging system was developed to image unerupted and erupted molars on test rats injected with ICG. Rats were injected with ICG and imaged using a variety of methods. Results show that for both erupted and unerupted molars occlusal wide-field imaging could identify the molar regions, and endoscopic imaging could clearly identify molar morphology including crowns and cusps. Fluorescent intensity data was collected using a spectrometer and analyzed to determine the optimized imaging window for the NIR dental imaging system. Further experiments were conducted to test the system’s imaging capability on rat molars treated with laser ablation treatment, and on human teeth. We are the first group to develop and test a cost and time efficient, safe, and real-time NIR-Ⅰ fluorescent imaging system for in-situ dental imaging

The Issue of Cyberbullying: A Literature Review

This paper will examine current literature regarding cyberbullying. First, cyberbullying will be defined and then, the differences between direct bullying and cyberbullying will be considered. Statistics that pertain to cyberbullying, factors regarding who is cyberbullied and who cyberbullies and what teachers can do to help will be examined. Cyberbullying is an issue that many adolescents face. As adults that spend many hours with these adolescents, teachers can make a big difference. The purpose of this paper is to review current research in order to help educate teachers on cyberbullying and how they can help

Glyphosate - A Review

In recent years, a large number of herbicides based on the active ingredient glyphosate have been introduced. All claim to be as good, or better, than the original Roundup. The ingredient statements on the label provides little help in differentiating the products since the contents are broken down simply as \u27active\u27 and \u27inert\u27 or \u27other\u27 ingredients. This article will discuss how the contents of the glyphosate products may vary and factors that influence the performance of glyphosate

Palmer amaranth: ID, biology and management

Palmer amaranth is native to the Southwestern United States, but its range has expanded over the past 50 years. The first documented occurrence in Iowa was this year, although with these infestations it is clear that the weed was initially introduced to the state prior to 2013. It has been a serious problem in the south, and gained national notoriety after developing resistance to glyphosate and devastating the cotton industry in the Southeast. This paper will review why the weed has garnered such attention and access the threat it poses to Iowa

Off-target Dicamba Injury: The Iowa Experience

The problems experienced with off-target movement and injury in states south of Iowa, particularly Missouri, Arkansas and Tennessee have been well covered in the press, but there has been little discussion of problems in Iowa. Unfortunately, the lack of press does not mean everything has gone smoothly in the state. While I don’t know the percentage of Xtend soybean fields experiencing problems with off-target movement, in my mind the number is too high

Weed Seeds- The Source of all Problems

The primary reason for controlling weeds during crop production is to prevent crop yield losses due to competition with weeds. However, the majority of Iowa farmers strive to obtain higher levels of weed control than necessary to protect crop yields. The rationale for this contradiction is the concern about the production of seeds by weeds left in the field. Since the majority of weeds found in Iowa row crops are summer annuals, the seed bank is the source of new weed infestations each spring. The seedbank influences both the weed populations that occur in a field and the success of weed management programs. The weed seed cycle is depicted in Figure 1. The size of the seedbank fluctuates widely depending on the magnitude of seed introductions and seed losses. Weeds are legendary for their capacity to produce seeds and for the longevity of these seeds in the soil. While there is no doubt that weeds can be quite remarkable in these aspects, the capabilities of weeds are often exaggerated. This paper will discuss the different components of the weed seed cycle and the importance of the seed bank to weed management

Where Will Our Next Major Weed Problems Come From?

Weed communities within agronomic fields are defined by the number of different species present and the relative abundance of the individual species. At any given time, three or four species within a field typically dominate the weed community, with the remaining species present at relatively low densities. A weed shift represents a change in the weed community within a field. The majority of shifts are caused by differential selection pressure placed on the weeds present in a field. Species or biotypes adapted to current weed management tactics increase, whereas weeds susceptible to those tactics decrease. The rate of change varies with the characteristics of the weed species and the diversity of the control tactics used in a field. Occasionally, weed shifts occur due to the introduction of a new species to a region. This paper will provide an overview of characteristics that allow certain plants to become invasive and expand their range by invading new regions