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Studies of post-mortem human tissue provide insight into pathological processes, but are inherently limited by practical considerations that limit the scale at which tissue can be examined, and the obvious issue that the tissue reflects only one time point in a continuous disease process. We approached this problem by adapting new tissue clearance techniques to an entire cortical area of human brain, which allows surveillance of hundreds of thousands of neurons throughout the depth of the entire cortical thickness. This approach allows detection of ‘rare’ events that may be difficult to detect in standard 5 micrometre-thick paraffin sections. For example, it is well established that neurofibrillary tangles begin within a neuron, and ultimately, in at least some instances, persist in the brain even after the neuron has died. These are referred to as ‘ghost tangles’, a term that appropriately implies their ‘difficult to see’ ephemeral qualities. We set out to find ghost tangles as one example of the power of the tissue clearance/image analysis techniques to detect rare events, and to learn what happens at the end-point of a tangle’s life history. We were able to identify 8103 tau tangles, 132 465 neurons and 299 640 nuclei in tissue samples from three subjects with severe Alzheimer’s disease (Braak V–VI) and 4 tau tangles, 200 447 neurons and 462 715 nuclei in tissue samples from three subjects with no significant tau pathology (Braak 0–I). Among these data, we located 57 ghost tangles, which makes them only 0.7% of the total tau tangles observed. We found that ghost tangles are more likely to be found in cortical layers 3 and 5 (49/57), with a select few scattered across other layers 1, 2, 4 and 6. This ability to find rare events, such as ghost tangles, in large enough quantities to statistically test their distribution exemplifies how tissue clearing can be used as a powerful tool for studying selective vulnerability or resilience to pathology across brain regions.

Whole grain foods have been associated with health benefits, yet are underconsumed by youth compared to recommendations. This study evaluated impacts of a school-based curriculum among children in grades 3-5 to address barriers to intake (2018-2019) (n = 1,748). Surveys before and after the program indicated youth were more willing to try and better able to identify whole grain foods. Open-ended responses confirmed findings regarding increased ability to identify whole grain foods, increased preferences and perceptions of availability. Together, these impacts could increase the likelihood that youth can meet whole grain intake recommendations to improve diet quality and health.

Hypervelocity impacts frequently result in the formation of dikes in the crater floor and central uplift. Impact melt-bearing dikes in large terrestrial impact basins – such as the Offset Dikes at the Sudbury impact structure – occur at a large scale, often tens of meters wide and several kilometers in length. The Offset Dikes host significant Ni–Cu–PGE deposits, which include several well-known mines, such as Totten and Copper Cliff that have been mined for nearly 100 years. The Offset Dikes typically consist of a clast- and sulfide-rich core and clast-poor margins. Their formation has been a subject of debate for decades. The most widely proposed model is the early emplacement of clast-poor impact melt shortly after the impact event, followed by the later emplacement of clast- and sulfide-rich impact melt in the center of the dike. An alternative hypothesis is that a single pulse of clast-rich impact melt flowed into the fractured target rocks and flow differentiation resulted in a clast-rich core and a clast-poor margin. In this study, we examine field and petrographic relationships of the Foy Offset Dike to better understand its emplacement. Our results show that the characteristics of the Foy Offset Dike – namely the gradational nature of the contact between the clast-rich and clast-poor phases, the alignment of clasts sub-parallel to this contact, the geochemical similarities and the presence of sulfides within both phases of the dike – are more consistent with the single injection and flow differentiation hypothesis.

The Offset Dykes are impact melt-bearing dykes related to the 1.85 Ga Sudbury impact structure. Currently, the dykes extend radially outward from—or occur concentrically around—the Sudbury Igneous Complex, which is the remnant of a differentiated impact melt sheet and the source of the dykes. The recently identified three Pele Offset Dykes intrude into the Archean rocks north of the Sudbury Igneous Complex. In this study, the Pele dykes are characterized for the first time by a combination of fieldwork, optical microscopy, electron microprobe analyses, and bulk geochemical analyses. The Pele Offset Dykes stand out from the other Offset Dykes at Sudbury in two significant ways: (i) All other known Offset Dykes consist of an inclusion-rich lithology in the center of the dyke and an inclusion-poor lithology along the margins. The Pele dykes, however, are only composed of the inclusion-poor phase. (ii) The Pele dykes—particularly the Central and Eastern dykes—have a more evolved chemical composition relative to the other Offset Dykes. These observations suggest that the Pele dykes were emplaced after the other known Offset Dykes during two injection events: the Western followed by the Central and Eastern Pele dykes.

The purpose of the study was to compare the relationship between stride length (SL), stride frequency (SF), and velocity while running on a treadmill and overground. Participants (n=10; 22.3±2.6 yrs; 1.71±.08 m; 71.4±15.5 kg) completed a total of 14 runs (7 treadmill, 7 overground) with each run at a different velocity. SL, SF, and velocity data were recorded using wearable technology (Garmin, Fenix2). The outdoor trials occurred first. The treadmill velocities were selected to match the range of velocities used overgroud. SL vs. velocity plots were generated for treadmill and overground data for each participant and fit with a 2nd order polynomial in the form of SL=Av2+Bv+C. Each equation coefficient (i.e., A, B, C) was averaged across participants and compared between treadmill and overground using paired t-tests. The A coefficient (v2 term) was different treadmill vs. overground (p=0.031). Neither B (p=0.136) nor C (p=0.260) coefficients were different treadmill vs. overground. It was concluded that the A coefficient (v2 term) for SL vs. velocity was larger during overground vs. treadmill running. This is an indication that the strategy of changing SL across velocities was different when on the treadmill vs. overground. Specifically, while running on a treadmill, SL continued to increase in a more linear manner than when running overground.

Object Simulation has become an important tool in neurosurgical education as part of the complex process of improving residents' technical expertise while preserving patient safety. Although different simulators have already been designed for a variety of neurosurgical procedures, spine simulators are still in their infancy and, at present, there is no available simulator for lumbar spine pathologies in pediatric neurosurgery. In this paper the authors describe the peculiarities and challenges involved in developing a synthetic simulator for pediatric lumbar spine pathologies, including tethered spinal cord syndrome and open neural tube defects. Methods The Department of Neurosurgery of the University of Illinois at Peoria, in a joint program with the Mechanical Engineering Department of Bradley University, designed and developed a general synthetic model for simulating pediatric neurosurgical interventions on the lumbar spine. The model was designed to be composed of several sequential layers, so that each layer might closely mimic the tensile properties of the natural tissues under simulation. Additionally, a system for pressure monitoring was developed to enable precise measurements of the degree of manipulation of the spinal cord. Results The designed prototype successfully simulated several scenarios commonly found in pediatric neurosurgery, such as tethered spinal cord, retethered spinal cord, and fatty terminal filum, as well as meningocele, myelomeningocele, and lipomyelomeningocele. Additionally, the formulated grading system was able to account for several variables involved in the qualitative evaluation of the technical performance during the training sessions and, in association with an expert qualitative analysis of the recorded sessions, proved to be a useful feedback tool for the trainees. Conclusions Designing and building a synthetic simulator for pediatric lumbar spine pathologies poses a wide variety of unique challenges. According to the authors' experience, a modular system composed of separable layers that can be independently replaced significantly enhances the applicability of such a model, enabling its individualization to distinctive but interrelated pathologies. Moreover, the design of a system for pressure monitoring (as well as a general score that may be able to account for the overall technical quality of the trainee's performance) may further enhance the educational applications of a simulator of this kind so that it can be further incorporated into the neurosurgical residency curriculum for training and evaluation purposes.

La mine Thayer Lindsley, situee sur le flanc sud du complexe igne de Sudbury (1.85 Ga), fournit un exemple d'une mineralisation en sulfures de Ni-Cu-EGP pres du contact et en sulfures de Cu-Ni-EGP dans la paroi inferieure (EGP: elements du groupe du platine). Ici, nous traitons des zones de minerai pres du contact; elles sont affectees par des zones de cisaillement dans un encaissant recristallise au facies amphibolite inferieur; celles -ci deplacent le contact entre le complexe igne et les roches paleoproterozoiques de la Province du Sud. Le minerai fortement deforme est largement appauvri en Ni et enrichi en Pt et Pd par rapport au minerai non deforme; de plus, la pentlandite se voit remplacee par la pyrrhotite, et la pyrrhotite, par pyrite et marcasite. Quoique les variations dans la teneur en metal de minerai sulfure magmatique soient en general attribuables a des processus primaires, impliquant par exemple le facteur R, la cristallisation fractionnee d'une solution solide monosulfuree, et des variations en fugacite de l'oxygene, f(O 2 ), aucune de ces hypotheses peut rendre compte de la teneur variable en Ni des minerais a la mine Thayer Lindsley. L'appauvrissement en Ni dans le minerai deforme refleterait plutot le remplacement de la pentlandite par la pyrrhotite, accompagne d'une remobilisation du Ni ainsi libere. Le taux de remplacement de la pentlandite est plus marque dans le minerai le plus fortement deforme; il est associe a une forte densite de veines de quartz syntectoniques. Une permeabilite accrue au cours du cisaillement a facilite le remplacement de la pentlandite et la mobilisation ou la perte de Ni grâce aux fluides en circulation dans les assemblages metamorphiques encaissants aux conditions du facies amphibolite.

The Thayer Lindsley mine is located in the South Range of the Sudbury impact structure, near the contact between the 1.85 Ga Sudbury Igneous Complex (SIC) and the Paleoproterozoic Southern Province. Ni–Cu ore zones at the mine are strongly deformed within a southeast-dipping, lower amphibolite-grade shear zone, which offsets the contact between the SIC and Southern Province rocks. Numerous shear sense indicators, including shear bands, drag folds, and δ- and σ-type rotated porphyroclasts, consistently indicate south-over-north, reverse, dip-slip movement parallel to the mineral stretching lineation in the shear zone. The attitude, slip direction, and metamorphic grade of the shear zone are similar to those of the regional northeast-striking South Range Shear Zone that formed during post-impact, northwest-directed ductile contraction of the Sudbury impact structure. The South Range Shear Zone is generally interpreted as a ca. 1.9–1.8 Ga Penokean structure. Anhedral brown titanite grains from the Thayer Lindsley shear zone yield a mean 207Pb/206Pb Penokean age of 1815 ± 15 Ma. These grains are mantled by younger, syntectonic, colourless titanite, which have a mean 207Pb/206Pb age of 1658 ± 68 Ma. This younger age suggests that the South Range and Thayer Lindsley shear zones may have formed during a 1.7–1.6 Ga collisional tectonic event that is recorded along the southeast margin of Laurentia from the southwest USA. (Mazatzal Orogeny), through the mid-continent to Wisconsin, and as far northeast as Labrador (Labradorian Orogeny). 40Ar/39Ar analyses indicate post-tectonic thermal resetting of biotite occurred at 1477 ± 8 Ma during felsic plutonism across the Sudbury area.

Medical simulation is a developing field used in the education of medical students, doctors, residents, and many other medical professionals. Despite emerging simulation tools, little has been done to address surgeries in congenital patients, specifically with regards to the spinal cord. The objective of this project was to design, fabricate, and functionally evaluate a medical simulator to address the challenge of teaching the spinal detethering surgical procedure to neurosurgery residents. This simulator was designed to mimic anatomical and physiological characteristics of the lower lumbar region. Pressure sensors were used to quantify the forces that were applied to the spinal cord during the surgical procedure and a LabVIEW program was developed to monitor the pressure profile. The simulator was functionally evaluated by six residents, one fellow, one doctor, and two medical students. A conclusive, quantitative method for scoring these surgeries has not yet been developed, however, the residents and medical students were able to compare their procedures with those of more experienced doctors and fellows via qualitative methods. Future developments will include incorporating quantitative scoring methods as well as noise elimination hardware into the design.

The 439 amino acid yeast Gcn5 protein contains a C-terminal bromodomain, which is required for SAGA (Spt-Ada-Gcn5-Acetyltransferase) mediated nucleosomal acetylation and transcriptional coactivation. Bromodomains are acetyl-lysine binding modules found in many chromatin binding proteins and histone acetyltransferases. Recently, both in vivo and in vitro studies indicate that bromodomains are able to discriminate the acetylation state of lysine side-chains within histone proteins. Here, the cloning, expression and bioactivity of a recombinant bromodomain from the yeast Gcn5 protein is described. The bromodomain from Gcn5 was cloned from yeast genomic DNA enabling effective one-step purification by affinity chromatography. Steady-state fluorescence anisotropy was used to quantify the interaction of Gcn5 with acetylated histone H3. The present cloning, expression, and purification procedure enabled the preparation of large quantity and high yields of biologically active recombinant Gcn5 bromodomain for in vitro structure and function studies.

High-frequency EEG (HFE) as a potential predictor of alertness/drowsiness was first proposed by Kaplan and Loparo. Sampling EEG at 950 Hz, they established an HFE bandwidth of interest ranging from 100-475 Hz. We extend their work by applying discrete Fourier transform (DFT) of HFE signals sampled at 1000 Hz and partitioned into spectral bands along specific frequency ranges for the assessment of sleep-wake state transition, sleep, and active cognitive engagement.There were 13 volunteers (6 men, 7 women, 30 +/- 3 yr) who participated in a 40-h sleep-deprivation study, during which time they performed multiple cognitive tasks. EEG, in synchrony with other physiological signals, was collected at a sampling rate of 1000 Hz. EEG and task performance results from two volunteers are discussed in this preliminary analysis of the C3-C4 region data. Spectral components obtained from DFT are delineated into five main frequency bands: low, (LFB, 1-15 Hz); intermediate (IFB, 16-50 Hz); and 3 high frequency bands: HFB1 (51-100 Hz); HFB2 (101-200 Hz); and HFB3 (201-500 Hz) for analysis purposes.LFB in the 1-15 Hz range at 0.40 spectrum proportion indicated declining alertness; LFB above 0.50 signals transition to sleep; and LFB at 0.70 indicates Stage 2/3 sleep. HFB3 in the 201-500 Hz range at 0.25 and above was a marker of cognitive function and/or capacity.HFE may provide a quantitative measure of cognitive function capacity. LFB may provide a measure for awake, asleep, or awake-sleep transition, and HFB3 an estimate of cognitive task engagement. HFE may be applied for electroencephalographic monitoring of cognitive performance.