Creating research spaces for underserved communities: Expanding and extending intersectionality in contemporary educational contexts

Methods: Intersectionality has extended beyond the tenets of race, gender and class to include queer communities, religious issues, literacy concerns, pedagogical styles, etc. in South Africa, the European Union and beyond. Intersectionality is no longer solely relegated to the needs of African American women germane to the United States. Aim(s): This paper is also aimed at engaging researchers and practitioners in an intellectual dialog that may contribute to the ever-expanding research on intersectionality to include the United States, European Union, South Africa and other global communities. Background: Educators are cognisant of the dense demographic shifts and inequities in primary and secondary schools. The call for guidance, resources and policy is critically needed; the disproportionalities consistent in schools have manifested themselves in school disciplinary practices and student achievement. The manuscript encourages discourse and provides a roadmap to examine intersectionality’s expansion critically and how that expansion can aid in improving the lives of K-12 public education students on an international scale. Additionally, the manuscript addresses whether intersectionality or its expansion served as a pivotal voice for marginalised communities and structures domestically and abroad

Helium distributions in ocean island basalt olivines revealed by X-ray computed tomography and single-grain crushing experiments

X-ray computed tomography of individual olivine crystals in basalts from Ofu and Olosega islands, American Samoa, reveals that a small fraction of the olivines contain the vast majority of the fluid inclusions. Single-grain crushing experiments demonstrate that He and CO_2 reside primarily in these inclusions. Low CO_2 pressures in most grains, corresponding to depths of less than 1 km, provide evidence of ubiquitous decrepitation and associated pressure reduction in the fluid inclusions. Even so, the olivines with the highest inclusion volumes yielded sufficient He to obtain precise He concentrations and isotopic compositions. Within analytical uncertainty, ^3He/^4He ratios are homogeneous among the olivines from each basalt, but among basalts, the ratios range from 21 to 35 Ra. The total range in C/^3He ratio within the analyzed olivines is from 3.6 × 10^7 to 1.5 × 10^(10), and varies by nearly an order of magnitude within the olivines from each basalt. We postulate that this wide range of C/^3He ratios is caused by grain-scale decoupling of C and ^3He due to extensive He diffusion out of fluid inclusions through the olivine lattice during magma ascent and cooling. If so, primary Ofu-Olosega magmas probably had C/^3He ratios less than 4 × 10^8, which is lower than previous estimates for hotspot magmas

Exposure to Nickel, Chromium, or Cadmium Causes Distinct Changes in the Gene Expression Patterns of a Rat Liver Derived Cell Line

Many heavy metals, including nickel (Ni), cadmium (Cd), and chromium (Cr) are toxic industrial chemicals with an exposure risk in both occupational and environmental settings that may cause harmful outcomes. While these substances are known to produce adverse health effects leading to disease or health problems, the detailed mechanisms remain unclear. To elucidate the processes involved in the toxicity of nickel, cadmium, and chromium at the molecular level and to perform a comparative analysis, H4-II-E-C3 rat liver-derived cell lines were treated with soluble salts of each metal using concentrations derived from viability assays, and gene expression patterns were determined with DNA microarrays. We identified both common and unique biological responses to exposure to the three metals. Nickel, cadmium, chromium all induced oxidative stress with both similar and unique genes and pathways responding to this stress. Although all three metals are known to be genotoxic, evidence for DNA damage in our study only exists in response to chromium. Nickel induced a hypoxic response as well as inducing genes involved in chromatin structure, perhaps by replacing iron in key proteins. Cadmium distinctly perturbed genes related to endoplasmic reticulum stress and invoked the unfolded protein response leading to apoptosis. With these studies, we have completed the first gene expression comparative analysis of nickel, cadmium, and chromium in H4-II-E-C3 cells

Reverse-engineering the cortical architecture for controlled semantic cognition.

We employ a reverse-engineering approach to illuminate the neurocomputational building blocks that combine to support controlled semantic cognition: the storage and context-appropriate use of conceptual knowledge. By systematically varying the structure of a computational model and assessing the functional consequences, we identified the architectural properties that best promote some core functions of the semantic system. Semantic cognition presents a challenging test case, as the brain must achieve two seemingly contradictory functions: abstracting context-invariant conceptual representations across time and modalities, while producing specific context-sensitive behaviours appropriate for the immediate task. These functions were best achieved in models possessing a single, deep multimodal hub with sparse connections from modality-specific regions, and control systems acting on peripheral rather than deep network layers. The reverse-engineered model provides a unifying account of core findings in the cognitive neuroscience of controlled semantic cognition, including evidence from anatomy, neuropsychology and functional brain imaging

Geodynamic implications for zonal and meridional isotopic patterns across the northern Lau and North Fiji Basins

We present new Sr-Nd-Pb-Hf-He isotopic data for sixty-five volcanic samples from the northern Lau and North Fiji Basin. This includes forty-seven lavas obtained from forty dredge sites spanning an east-west transect across the Lau and North Fiji basins, ten ocean island basalt (OIB)-type lavas collected from seven Fijian islands, and eight OIB lavas sampled on Rotuma. For the first time we are able to map clear north-south and east-west geochemical gradients in 87Sr/86Sr across the northern Lau and North Fiji Basins: lavas with the most geochemically enriched radiogenic isotopic signatures are located in the northeast Lau Basin, while signatures of geochemical enrichment are diminished to the south and west away from the Samoan hotspot. Based on these geochemical patterns and plate reconstructions of the region, these observations are best explained by the addition of Samoa, Rurutu, and Rarotonga hotspot material over the past 4 Ma. We suggest that underplated Samoan material has been advected into the Lau Basin over the past ∼4 Ma. As the slab migrated west (and toward the Samoan plume) via rollback over time, younger and hotter (and therefore less viscous) underplated Samoan plume material was entrained. Thus, entrainment efficiency of underplated plume material was enhanced, and Samoan plume signatures in the Lau Basin became stronger as the trench approached the Samoan hotspot. The addition of subducted volcanoes to the Cook-Austral Volcanic Lineament material, first from the Rarotonga hotspot, then followed by the Rurutu hotspot, contributes to the extreme geochemical signatures observed in the northeast Lau Basin

Insulin Sensitivity Effects on Peripheral Vascular Responses to FMD in Metabolic Syndrome Women.

Sedentary populations with obesity and metabolic syndrome (MetSyn) have presented with impaired vascular dysfunction, including vasodilation reduced 40-50%. The mechanisms of vascular endothelial dysfunction has also been associated to the bioavailability of nitric oxide levels and in metabolic compromised individuals the diminished content of endothelial NO are a prime mechanistic target for study. PURPOSE: We hypothesize that decreased reactive hyperemia observed in MetSyn compared to age matched-control patients are primarily due to mechanistic dysfunction of the eNOS pathway and lower Insulin Sensitivity Index (ISI). METHODS: 30 participants (10 MetSyn and 20 Controls) completed brachial FMD testing and vascular changes were recorded using Doppler ultrasound with a linear vascular probe. A blood pressure cuff was placed on the upper forearm and upper calf for analysis of brachial and popliteal arteries sheer rate and reactive hyperemia. Images were analyzed with Brachial Analyzer software and sheer rate calculated by digital recordings of blood velocity with a digital auditory transducer recordings with a BIOPAC 150 system and AcqKnowlege software. Insulin sensitivity index was assessed by an oral glucose tolerance test with fasting and post-prandal glucose measured with a glucometer and insulin measured by a Human Insulin ELISA kit (Cayman Chemical). The resting bioavailability of Nitric Oxide assessed by Nitrate/Nitrite ELISA assay and NO EPR spectroscopy measurements. RESULTS: In the brachial arteries there is significant differences (PCONCLUSION: We predict that the significant deficiencies observed between the control and MetSyn group may be explained by the vascular mechanisms of developing deficits associated with the metabolic deficiencies. A postulated mechanism of this endothelial dysfunction during insulin resistance begins with the decreased sensitivity of the insulin receptor preventing the effect of insulin and the AKT/PKB eNOS pathway. Research reported in this publication was supported by an Institutional Development Award (IDeA) from the National Institute of General Medicine Sciences of the National Institutes of Health under grant number P20GM103451

Life, Death and Preferential Attachment

Scientific communities are characterized by strong stratification. The highly skewed frequency distribution of citations of published scientific papers suggests a relatively small number of active, cited papers embedded in a sea of inactive and uncited papers. We propose an analytically soluble model which allows for the death of nodes. This model provides an excellent description of the citation distributions for live and dead papers in the SPIRES database. Further, this model suggests a novel and general mechanism for the generation of power law distributions in networks whenever the fraction of active nodes is small.Comment: 5 pages, 2 figure

Contact-less measurements of Shubnikov-de Haas oscillations in the magnetically ordered state of CeAgSb2_2 and SmAgSb2_2 single crystals

Shubnikov - de Haas oscillations were measured in single crystals of highly metallic antiferromagnetic SmAgSb$_{2}$ and ferromagnetic CeAgSb$_{2}$ using a tunnel diode resonator. Resistivity oscillations as a function of applied magnetic field were observed via measurements of skin depth variation. The effective resolution of $\Delta\rho\simeq20$ p$\Omega$ allows a detailed study of the SdH spectra as a function of temperature. The effects of the Sm long - range magnetic ordering as well as its electronic structure ($4f$-electrons) on the Fermi surface topology is discussed