To determine the relationship of tobacco and marijuana smoking to levels of cadmium and zinc manifested in hair samples, a study was conducted at Portland State University using atomic.absorption spectrophotometry. 97 adult student volunteers participated in the main study.

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ABSTRACT This research report investigates the manifestation of hair as a symbol of cultural and gender identity as is seen in selected works of South African artist Tracey Rose, whose usage of her own culturally specific hair and body serves as metaphor through which she critically engages with issues surrounding the gendered and racialized body. The report will explore the ways in which Rose both in her video piece Ongetiteld (1996) and her performance video installation Span II (1997) challenges and subsequently deconstructs the rigidly defined monoliths of ‘Woman’, ‘femininity’, and the racially constructed category of ‘Coloured’, assigned and imposed on her during the Apartheid era. Rose’s work, highlighting the extent to which the conceptualization of gender and racial identity are bound and read off the body’s corporeality, relates to my own artistic practice, whereby I examine the metaphorical functioning of skin, as a corporeal ‘text’ and parchment, facilitating the inscription of my own cultural, religious and linguistic Otherness.

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[pt] O exame de mineralograma capilar fornece as concentrações de elementos tóxicos e essenciais no cabelo. O uso de produtos capilares, além de poderem representar uma fonte de exposição, é possível que causem alterações na composição mineral do cabelo. Neste trabalho, amostras de cabelo natural foram submetidas a tratamentos com diferentes tinturas e, posteriormente, analisadas seguindo a metodologia pré-estabelecida para determinação multielementar por espectrometria de massas com plasma indutivamente acoplado (ICP-MS). A composição elementar do cabelo humano natural foi comparada com as determinadas nas mesmas amostras de cabelo submetidas a tratamentos com diferentes tintas. Utilizando o teste estatístico Kruskal-Wallis, foi possível identificar diferenças significativas (p < 0,05) para os elementos Na, K e Mg, cujas concentrações aumentaram (de 100 a 5000x) após o uso das tinturas permanentes e semipermantes, enquanto para os cabelos que foram submetidos a tratamentos com corantes naturais isso não foi observado. Alguns elementos como Al, Fe, P tiveram decréscimo em suas concentrações (de 20 a 40%) após o uso desses tratamentos. Diante disso, foi possível determinar que alguns elementos são transferidos ou removidos do cabelo após o uso de determinados produtos, confirmando que tratamentos estéticos podem interferir nos resultados do exame do mineralograma capilar, devendo ser avaliada a necessidade da realização do mesmo em pacientes com cabelo tingido ou a possibilidade de aguardar por, pelo menos, 3 meses sem o uso de tratamentos permanentes antes da coleta da amostra para realização do exame. / [en] The hair mineral analysis test reports the concentrations of toxics and essential elements inside the hair structure. The utilization of hair care products, in addition to being able to represent an exposure source, also can be responsible for certain changes in the mineral composition of the hair. In present work, natural hair samples were treated with different dyes and, posteriorly, studied following the pre-established protocol for multi-element analysis by means of inductively coupled plasma mass spectrometry (ICP-MS). Hence, the element compositions of natural human hair after different treatments were compared. With the help of the Kruskal-Wallis statistical test, it was possible to identify significant differences (p < 0.05) for the elements, such as Na, K and Mg. Their concentrations increased from 100 to 5000x after the use of permanent and semipermanent dyes, while in the case of the hair samples treated with the natural dye no significant difference was observed. The concentrations of some elements, such as Al, Fe, P decreased (from 20 to 40%) after the respective treatments. Therefore, it was established that some elements are transferred or removed from the hair after the use of certain products, confirming that aesthetic treatments can interfere the results of the hair mineral analysis test. It reasons testing in patients with dyed hair or the possibility of waiting for about 3 months without the use of permanent treatments before sample collection for the analysis.

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A computational fluid dynamics (CFD) model is developed for pulsatile flows and particle transport to evaluate the possible thrombus trajectory in the feline aorta for Hypertrophic Cardiomyopathy (HCM) heart conditions. An iterative target mass flow rate boundary condition is developed, and turbulent simulations with Lagrangian particle transport model are performed using up to 11M grids. The model is validated for human abdominal aorta flow, for which the results agree within 11.6% of the experimental data. The model is applied for flow predictions in a generalized feline aorta for healthy and HCM heart conditions. Results show that in the HCM case, the flow through the iliac arteries decreases by 50%, due to the large recirculation regions in the abdominal aorta compared to the healthy heart case. The flow recirculation also result in stronger vortices with slower decay, causing entrapment of particles in the thoracic aorta and trifurcation regions.

Researchers have investigated several factors that could alter fetal growth, including nutrient restriction (Valiente et al., 2021), hair shedding (Gray et al., 2011), and extreme hot and cold temperatures (Davidson et al., 2022). Hot temperatures and increased humidity percentages in the southeast United States caused researchers to investigate the hair coats of Angus cattle in the commercial production setting. An improvement in fiber digestibility and calf birth and weaning weights has been observed in Angus dams that shed 50% of the winter hair coat by May (Gray et al., 2011; Burnett et al., 2021). Our objective of this experiment was to investigate the nutrient digestibility of Angus calves born to cows that on average, shed early compared to calves from cows that shed later. Newly weaned, purebred Angus bull calves (early; n = 6, late; n = 6) were housed in metabolism crates for 10 d. Prior to the trial, calves had a 14 d adaption period to a 14% CP textured feed (CPC 14% Developer, CPC Commodities, Fountain Run, KY) and offered ad libitum Cynodon dactlyon hay and water. After 3 d crate acclimation period, urine, feces, orts, and hay samples were collected for 7 d. Concentrate was offered at 0.25% of average BW. Approximately 5% samples were taken of feces, and urine samples had 1-1.5% of 25% metaphosphoric acid added to prevent ammonia volatilization, and both collections were composited by animal. Orts were collected at 0600 h daily, dried, and composited by animal. Laboratory analysis included dry matter (DM), organic matter (OM), Ash, neutral detergent fiber (NDF), acid detergent fiber (ADF), Kjeldahl N (CP), and fat. Data were analyzed using the GLM procedure of SAS 9.4 in a completely randomized design with calf as the experimental unit. Significant (P ≤ 0.05) means were separated using Fischer’s protected LSD. The model for intake included average daily DM and OM (kg) and adjusted by body weight (BW%). For digestibility analysis, the model included: DM, OM, ash, NDF, ADF, hemi-cellulose (HC), CP, and fat. The N retention model included: N retained (g/d), N retained/consumed (%), and N retained/DM intake (%). There were no differences between early or late calves for DM intake (5.502 ± 0.2774 kg/d; 2.251 ± 0.1247 %BW), or OM intake (5.199 ± 0.2591 kg/d; 2.128 ± 0.1166 %BW). There were no differences in digestibility for either group for DM, OM, Ash, NDF, ADF, HC, CP, or fat (Table 1.). There were also no differences in N retention in either group of calves (3.686 ± 2.0242 g/d; 4.366 ± 2.3964 %; 0.064 ± 0.0355 %). Replication and further research are needed in this area to adequately understand factors influencing nutrient digestibility in calves born from early and late shedding dams.

Spectral domain optical coherence tomography (OCT) is a powerful tool for measuring nanometer-scale displacement responses in the cochlea, as it is capable of volumetric imaging and vibrometry at a depth into a sample. The past decade has seen a wealth of OCT-measured displacement data from structures within the organ of Corti complex (OCC) that had previously been impossible to measure in vivo. These data have revealed surprising features of active intra-OCC motion but have not yet led to a complete understanding of cochlear amplification, the means by which active processes enhance the tuning and gain of the cochlear displacement responses in a level-dependent manner. Certain technical challenges arise from the properties of OCT imaging and vibrometry that obscure the interpretation of intra-OCC displacement measurements. In particular, OCT-measured responses are dependent on the orientation of the system's beam axis. The beam axis is generally chosen based on experimental convenience, and has no inherent relevance to the anatomy of the cochlea. This introduces two problems: 1) OCT-acquired images of the cochlea may be taken at skewed angles relative to the cochlea's naturally endowed anatomical coordinates, and 2) OCT-measured displacement responses are projections of a three-dimensional motion onto the beam axis. This thesis concerns the quantification of these effects on intra-OCC displacement measurements, as well as the development of methods to overcome these complications in vivo. In doing so, previously reported data that appear to disagree can be synthesized. I present a method by which the skew of OCT images relative to cochlear anatomy can be quantified, relating the OCT system's optical coordinates to the cochlear anatomy. With this method, I have shown that OCT images resembling familiar anatomical drawings of longitudinal cross-sections often capture a completely different anatomical slice of the cochlea. This leads to large quantitative shifts in phase responses when measuring displacements along a single beam axis, as opposed to what one would measure if s/he were measuring along an anatomically relevant axis. I have also provided a method by which to account for this phenomenon to capture structures related in some desired anatomical fashion. I then turn to the issue of projection of the three-dimensional cochlear motion onto the OCT beam axis. I have provided a method for reconstructing two- and three-dimensional displacement responses in the relevant anatomical directions by acquiring displacement measurements at multiple locations within the cochlea. In doing so, I have revealed that previously unexplained disagreements between measurements in different experimental preparations can be explained by competing components of motion being projected onto the single axis. I have also shown that motion at the junction between the outer hair cells and Deiters cells follows a lineal pattern, as opposed to non-degenerate elliptical patterns that would be expected of fluid motion in this region. This method requires the acquisition of data at many points within the OCC, making it significantly time-consuming. This makes it vulnerable to sample drift and deterioration, and reduces experimental yield. Certain applications of the method -- such as reconstructing displacement maps over a dense volume -- are thereby intractable. To address this problem, I have developed a compressed sensing method for vibrometry (CSVi). CSVi is a classical optimization method based on a total generalized variation signal prior, which is shown to out-perform methods using total variation and wavelet domain sparsity priors. I have also found that uniform sub-sampling schema offered significant performance benefits over random sub-sampling schema. I found that this CSVi method can reconstruct densely sampled displacement maps in the cochlea in vivo with less than 5% normalized mean square error, using only 10% of samples. While these methods offer new insight into interpretation of OCT displacement measurements, there is still a challenge in measuring the motion of the stereocilia of the hair cells. The stereocilia are too small to be imaged using OCT, and the proxy measurement of differential motion of the reticular lamina and tectorial membrane (between which the stereocilia lie) is not yet achievable in the gerbil base. Stereocilia motion is related to the transduction current through the hair cells, which is critical to understanding cochlear function. These currents lead to neurotransmitter release and active electromotile responses believed to be responsible for cochlear amplification. I present a model for studying another proxy measurement of the stereocilia motion -- the voltage in the cochlea's scala tympani, or cochlear microphonic (CM). This model of CM reveals that to match experimental data 1) stereocilia motion must be more sharply tuned than measured intra-OCC displacement responses, 2) the displacement-current gain of the mechano-electric transducer channels in vivo must be larger than what is measured in vitro by a factor of ~6, and 3) the hair cells at more basal locations of the cochlea must be compromised. These predictions offer insight into aspects of cochlear mechanics that are not easily probed using OCT.