1,449 research outputs found

    Proposition 67: Ban on Single-Use Plastic Bags

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    Exploring the Experiences and Perceptions of 21st Century Leadership Academy Participants

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    The 21st Century Leadership Academy grew out of an effort by the Council of Technology Teacher Education’s (CTTE) Leadership Development Committee to prepare future leaders for the field of Technology & Engineering Education (TEE). Efforts by Drs. Roger Hill (University of Georgia) and Bill Havice (Clemson University) led to the creation, and subsequent implementation, of this leadership academy with support from CTTE (later renamed the Council on Technology & Engineering Teacher Education [CTETE]) and the International Technology & Engineering Education Association (ITEEA). Initially, participation in the leadership academy was focused on early-career university faculty but recruitment was later expanded to include individuals with related professional experience (e.g., graduate students, tenured faculty members, etc.) and, as of January 2021, more than 80 individuals have participated in the academy. This study reports an investigation into the experiences and perceptions of the academy alums with an additional focus on their professional involvement, how participation may have influenced these activities, and suggestions they had for future cohorts. In addition, our investigation provides suggestions for future similar leadership training efforts that could be applied in a variety of fields. Our efforts, as researchers, aim to present the shared experience as navigated by the cohort participants. Although individual takeaways vary, overall themes such as networking and collaboration underscore the experience of participants in each cohort year. While participants consider themselves active in the field of Technology & Engineering Education, few of them are serving in leadership roles within CTETE or ITEEA

    Methodological implications of intra- and inter-facet microwear texture variation for human childhood paleo-dietary reconstruction: Insights from the deciduous molars of extant and medieval children from France

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    The present study concerns occlusal dental microwear texture variation on the deciduous molars of children. A description and evaluation of microwear texture variation within facet 9 and a comparison of microwear textures between grinding facets 9 and 11 are presented. The relationship between wear facet surface area and intra-facet microwear texture variability is evaluated. The sample is composed of naturally-exfoliated, taphonomy-free deciduous second molars from twelve extant children and four archaeologically-derived medieval children (for a total of 51 surface measurements). Dental microwear texture analysis (DMTA) was performed using a confocal microscope and scale-sensitive fractal analysis (SSFA) at three standardized locations on facet 9, and one location on facet 11. Facet shape was visually assessed and scored using a headset magnifier (3×) and composite images (20× confocal microscopy). Individuals were assigned to two groups based on a qualitative assessment of facet surface area. Microwear texture variability within facet 9 was high relative to the variability of microwear textures between individuals. No significant inter-facet variation between facets 9 and 11 was detected. No clear differences in microwear and variabilities within facet 9 were found between individuals assigned to small and large facet groups. Our study shows the existence of important intra-facet microwear variation in a sample of children. Intra-facet microwear variation can affect the ability of DMTA to distinguish between diets in contexts with small sample sizes and subtle differences in diet – such as those characterizing dietary transitions in children. Results also suggest non-dietary factors may influence microwear formation during dental exfoliation. A better understanding of intra-facet microwear variation, and when and how to account for it, can improve the application of occlusal DMTA in similar contexts

    Differential regulation of gene expression pathways with dexamethasone and ACTH after early life seizures.

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    Early-life seizures (ELS) are associated with persistent cognitive deficits such as ADHD and memory impairment. These co-morbidities have a dramatic negative impact on the quality of life of patients. Therapies that improve cognitive outcomes have enormous potential to improve patients\u27 quality of life. Our previous work in a rat flurothyl-induction model showed that administration of adrenocorticotropic hormone (ACTH) at time of seizure induction led to improved learning and memory in the animals despite no effect on seizure latency or duration. Administration of dexamethasone (Dex), a corticosteroid, did not have the same positive effect on learning and memory and has even been shown to exacerbate injury in a rat model of temporal lobe epilepsy. We hypothesized that ACTH exerted positive effects on cognitive outcomes through beneficial changes to gene expression and proposed that administration of ACTH at seizure induction would return gene-expression in the brain towards the normal pattern of expression in the Control animals whereas Dex would not. Twenty-six Sprague-Dawley rats were randomized into vehicle- Control, and ACTH-, Dex-, and vehicle- ELS. Rat pups were subjected to 60 flurothyl seizures from P5 to P14. After seizure induction, brains were removed and the hippocampus and PFC were dissected, RNA was extracted and sequenced, and differential expression analysis was performed using generalized estimating equations. Differential expression analysis showed that ACTH pushes gene expression in the brain back to a more normal state of expression through enrichment of pathways involved in supporting homeostatic balance and down-regulating pathways that might contribute to excitotoxic cell-damage post-ELS

    State-Dependent Differences in Functional Connectivity in Young Children With Autism Spectrum Disorder

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    AbstractBackgroundWhile there is increasing evidence of altered brain connectivity in autism, the degree and direction of these alterations in connectivity and their uniqueness to autism has not been established. The aim of the present study was to compare connectivity in children with autism to that of typically developing controls and children with developmental delay without autism.MethodsWe assessed EEG spectral power, coherence, phase lag, Pearson and partial correlations, and epileptiform activity during the awake, slow wave sleep, and REM sleep states in 137 children aged 2 to 6years with autism (n=87), developmental delay without autism (n=21), or typical development (n=29).FindingsWe found that brain connectivity, as measured by coherence, phase lag, and Pearson and partial correlations distinguished children with autism from both neurotypical and developmentally delayed children. In general, children with autism had increased coherence which was most prominent during slow wave sleep.InterpretationFunctional connectivity is distinctly different in children with autism compared to samples with typical development and developmental delay without autism. Differences in connectivity in autism are state and region related. In this study, children with autism were characterized by a dynamically evolving pattern of altered connectivity

    Marfan syndrome : a case report and pictorial essay

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    We report a case of Marfan syndrome (MFS) in a South African patient, which is extraordinary because of the large constellation of clinical, radiological and vascular anomalies in a single patient. A literature search from 1950 to date did not show a similar report of such extensive clinical characteristics of MFS.http://www.panafrican-med-journal.comam2019Cardiolog

    Functional Network Changes in Hippocampal CA1 after Status Epilepticus Predict Spatial Memory Deficits in Rats

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    Status epilepticus (SE) is a common neurological emergency, which has been associated with subsequent cognitive impairments. Neuronal death in hippocampal CA1 is thought to be an important mechanism of these impairments. However, it is also possible that functional interactions between surviving neurons are important. In this study we recorded in vivo single-unit activity in the CA1 hippocampal region of rats while they performed a spatial memory task. From these data we constructed functional networks describing pyramidal cell interactions. To build the networks, we used maximum entropy algorithms previously applied only to in vitro data. We show that several months following SE pyramidal neurons display excessive neuronal synchrony and less neuronal reactivation during rest compared with those in healthy controls. Both effects predict rat performance in a spatial memory task. These results provide a physiological mechanism for SE-induced cognitive impairment and highlight the importance of the systems-level perspective in investigating spatial cognition

    HI Observations of Interacting Galaxy Pair NGC 4038/9

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    We present the results of new radio interferometer HI line observations for the merging galaxy pair NGC 4038/9 (`The Antennae'), obtained using the Australia Telescope Compact Array. The results improve substantially on those of van der Hulst (1979) and show in detail the two merging galactic disks and the two tidal tails produced by their interaction. The small edge-on spiral dwarf galaxy ESO 572-G045 is also seen near the tip of the southern tail, but distinct from it. It shows no signs of tidal interaction. The northern tidal tail of the Antennae shows no HI connection to the disks and has an extension towards the west. The southern tidal tail is continuous, with a prominent HI concentration at its tip, roughly at the location of the tidal dwarf galaxy observed optically by Mirabel, Dottori & Lutz (1992). Clear velocity structure is seen along the tidal tails and in the galactic disks. Radio continuum images at 20-cm and 13-cm are also presented, showing the disks in detail.Comment: 22 pages, 8 figures, Accepted by MNRAS (April 2001

    Behavioral modifications by a large-northern herbivore to mitigate warming conditions

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    Background: Temperatures in arctic-boreal regions are increasing rapidly and pose significant challenges to moose (Alces alces), a heat-sensitive large-bodied mammal. Moose act as ecosystem engineers, by regulating forest carbon and structure, below ground nitrogen cycling processes, and predator-prey dynamics. Previous studies showed that during hotter periods, moose displayed stronger selection for wetland habitats, taller and denser forest canopies, and minimized exposure to solar radiation. However, previous studies regarding moose behavioral thermoregulation occurred in Europe or southern moose range in North America. Understanding whether ambient temperature elicits a behavioral response in high-northern latitude moose populations in North America may be increasingly important as these arctic-boreal systems have been warming at a rate two to three times the global mean. Methods: We assessed how Alaska moose habitat selection changed as a function of ambient temperature using a step-selection function approach to identify habitat features important for behavioral thermoregulation in summer (June–August). We used Global Positioning System telemetry locations from four populations of Alaska moose (n = 169) from 2008 to 2016. We assessed model fit using the quasi-likelihood under independence criterion and conduction a leave-one-out cross validation. Results: Both male and female moose in all populations increasingly, and nonlinearly, selected for denser canopy cover as ambient temperature increased during summer, where initial increases in the conditional probability of selection were initially sharper then leveled out as canopy density increased above ~ 50%. However, the magnitude of selection response varied by population and sex. In two of the three populations containing both sexes, females demonstrated a stronger selection response for denser canopy at higher temperatures than males. We also observed a stronger selection response in the most southerly and northerly populations compared to populations in the west and central Alaska. Conclusions: The impacts of climate change in arctic-boreal regions increase landscape heterogeneity through processes such as increased wildfire intensity and annual area burned, which may significantly alter the thermal environment available to an animal. Understanding habitat selection related to behavioral thermoregulation is a first step toward identifying areas capable of providing thermal relief for moose and other species impacted by climate change in arctic-boreal regions.publishedVersio

    Crosstalk between Desmoglein 2 and Patched 1 accelerates chemical-induced skin tumorigenesis

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    Aberrant activation of Hedgehog (Hh) signaling is causative of BCCs and has been associated with a fraction of SCCs. Desmoglein 2 (Dsg2) is an adhesion protein that is upregulated in many cancers and overexpression of Dsg2 in the epidermis renders mice more susceptible to squamous-derived neoplasia. Here we examined a potential crosstalk between Dsg2 and Hh signaling in skin tumorigenesis. Our findings show that Dsg2 modulates Gli1 expression, in vitro and in vivo. Ectopic expression of Dsg2 on Ptc1+/lacZ background enhanced epidermal proliferation and interfollicular activation of the Hh pathway. Furthermore, in response to DMBA/TPA, the Dsg2/Ptc1+/lacZ mice developed squamous lessons earlier than the WT, Ptc1+/lacZ, and Inv-Dsg2 littermates. Additionally, DMBA/TPA induced BCC formation in all mice harboring the Ptc1+/lacZ gene and the presence of Dsg2 in Dsg2/Ptc1+/lacZ mice doubled the BCC tumor burden. Reporter analysis revealed activation of the Hh pathway in the BCC tumors. However, in the SCCs we observed Hh activity only in the underlying dermis of the tumors. Furthermore, Dsg2/Ptc1+/lacZ mice demonstrated enhanced MEK/Erk1/2 activation within the tumors and expression of Shh in the dermis. In summary, our results demonstrate that Dsg2 modulates Hh signaling, and this synergy may accelerate skin tumor development by different mechanisms
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