Development and Evaluation of an Objective Method for Forensic Examination of Human Head Hairs Using Texture-Based Image Analysis

In response to criticism of traditional forensic methods of human head hair examination, the goal of this study was to develop and evaluate an objective method using texture-based image analysis. 120 individuals, including 20 from six different maternal groups, were sampled and their hairs evaluated using the developed method. Different variables were evaluated to develop the most efficient method to increase intra/inter ratio, as well as the percentage of well-classified hairs. The variables included different microscope systems, objective lenses, number of hairs examined per individual, hair shaft regions, focus methods, and normalization filter techniques. Statistical analyses included one-way analysis of variance, agglomerative hierarchical clustering, and classification trees. A tested method based on the combinations tested and a theoretical method based on evaluation of the performance of each variable were determined. The tested method revealed increased ratio of inter- and intra-variability and percentage of well-classified hairs when the reference population is decreased. The method also revealed percentages of well-classified hairs above 90% when comparing an individual to other members of the same maternal group, a comparison that would fail to differentiate if tested with mitochondrial DNA analysis. Future testing of the theoretical method, as well as further testing of maternal groups and population size, will need to be done to verify these results

Propeller propulsion integration, phase 1

A bibliography was compiled of all readily available sources of propeller analytical and experimental studies conducted during the 1930 through 1960 period. A propeller test stand was developed for the measurement of thrust and torque characteristics of full scale general aviation propellers and installed in the LaRC 30 x 60 foot full scale wind tunnel. A tunnel entry was made during the January through February 1980 period. Several propellers were tested, but unforseen difficulties with the shaft thrust torque balance severely degraded the data quality

Isotope labeling of Neurospora DNA

Isotope labeling of Neurospora DN

In vivo passage of Salmonella Typhimurium results in minor mutations in the bacterial genome and increases in vitro invasiveness

International audienceAbstractEggs and raw or undercooked egg-containing food items are frequently identified as the bacterial source during epidemiolocal investigation of Salmonella outbreaks. Multi-locus variable number of tandem repeats analysis (MLVA) is a widely used Salmonella typing method enabling the study of diversity within populations of the same serotype. In vivo passage, however, has been linked with changes in MLVA type and more broadly the Salmonella genome. We sought to investigate whether in vivo passage through layer hens had an effect on MLVA type as well as the bacterial genome and whether any mutations affected bacterial virulence. Layer hens were infected with either Salmonella Typhimurium DT9 (03-24-11-11-523) as part of a single infection or were co-infected with an equal amount of Salmonella Mbandaka. Salmonella shedding in both single and co-infected birds was variable over the course of the 16-week experiment. Salmonella Typhimurium and Salmonella Mbandaka were identified in feces of co-infected birds. Salmonella colonies isolated from fecal samples were subtyped using MLVA. A single change in SSTR-6 was observed in Salmonella Typhimurium strains isolated from co-infected birds. Isolates of Salmonella Typhimurium of both the parent (03-24-11-11-523) and modified (03-24-12-11-523) MLVA type were sequenced and compared with the genome of the parent strain. Sequence analysis revealed that in vivo passaging resulted in minor mutation events. Passaged isolates exhibited significantly higher invasiveness in cultured human intestinal epithelial cells than the parent strain. The microevolution observed in this study suggests that changes in MLVA may arise more commonly and may have clinical significance

Engaging nursing students and older adults through service-learning

Purpose The purpose of this study is to examine nursing students’ (n = 18) perceptions of interrelating with older adults to understand how such interactions might improve students’ levels of cultural competence and enhance their future nursing practice. Additionally, the study sought to contribute to a higher level of technological competency in older adults. Design/methodology/approach A basic qualitative study design (Merriam and Tisdell, 2016) was used to direct the data collection and analysis to achieve the aims of this study. Findings Four themes emerged from the data collected based on cultural knowledge, cultural skills, cultural desire and engaging in cross-cultural interactions. Students reflected on how their experiences would help them to interact with older adults in their future nursing practices. Research limitations/implications The limitation of the research is that the exploratory study cannot be generalized for a wider demographic. Also, the students’ prior experiences working with older adults were not considered and their reflections may not have accurately portrayed their true biases. Practical implications Reflection is a valuable practice to help students think through their experiences and is considered a key component of service-learning. In this study, students reflected on how their experiences would help them to interact with older adults in their future nursing practices. Social implications Nursing students who are later used take with them empathy, more sensitivity and positive attitudes toward older people to benefit the nurse-patient relationship with this population. Originality/value This is one of a handful of studies located that pairs nursing students with older people in teaching technology skills through iPad technology

Physical Electronics

Contains research objectives and reports on four research projects

Physical Electronics

Contains research objectives and reports on two research projects

Challenges in vaccinating layer hens against salmonella typhimurium

Salmonella Typhimurium is among the most common causes of bacterial foodborne gastrointestinal disease in humans. Food items containing raw or undercooked eggs are frequently identified during traceback investigation as the source of the bacteria. Layer hens can become persistently infected with Salmonella Typhimurium and intermittently shed the bacteria over the course of their productive lifetime. Eggs laid in a contaminated environment are at risk of potential exposure to bacteria. Thus, mitigating the bacterial load on farms aids in the protection of the food supply chain. Layer hen producers use a multifaceted approach for reducing Salmonella on farms, including the all-in-all-out management strategy, strict biosecurity, sanitization, and vaccination. The use of live attenuated Salmonella vaccines is favored because they elicit a broader host immune response than killed or inactivated vaccines that have been demonstrated to provide cross-protection against multiple serovars. Depending on the vaccine, two to three doses of Salmonella Typhimurium vaccines are generally administered to layer hens within the first few weeks. The productive life of a layer hen, however, can exceed 70 weeks and it is unclear whether current vaccination regimens are effective for that extended period. The objective of this review is to highlight layer hen specific challenges that may affect vaccine efficacy.Siyuan Jia, Andrea R. McWhorter, Daniel M. Andrews, Gregory J. Underwood and Kapil K. Chousalka

Electrical and Noise Characteristics of Graphene Field-Effect Transistors: Ambient Effects and Noise Sources

We fabricated a large number of single and bilayer graphene transistors and carried out a systematic experimental study of their low-frequency noise characteristics. A special attention was given to determining the dominant noise sources in these devices and the effect of aging on the current-voltage and noise characteristics. The analysis of the noise spectral density dependence on the area of graphene channel showed that the dominant contributions to the low-frequency electronic noise come from the graphene layer itself rather than from the contacts. Aging of graphene transistors due to exposure to ambient for over a month resulted in substantially increased noise attributed to the decreasing mobility of graphene and increasing contact resistance. The noise spectral density in both single and bilayer graphene transistors either increased with deviation from the charge neutrality point or depended weakly on the gate bias. This observation confirms that the low-frequency noise characteristics of graphene transistors are qualitatively different from those of conventional silicon metal-oxide-semiconductor field-effect transistors.Comment: 26 pages with 8 figure