Socio-spatial experiences of part-time community college faculty

2022 Spring.Includes bibliographical references.Nearly half of the undergraduate student population in the United States attends community colleges (Bailey, Jaggars, & Jenkins, 2015), and in serving these students, community colleges rely heavily on part-time faculty (Jaeger & Egan, 2009). The reliance on part-time faculty is typically cost-motivated and a symptom of the neoliberal influences on higher education (Levin, 2007; Saunders, 2008). Part-time faculty often lack resources and support, are poorly compensated, do not receive benefits, and their teaching schedules are inconsistent and unreliable (Caruth & Caruth, 2013). The purpose of this study was to examine the everyday lived experiences of part-time community college faculty through a socio-spatial lens. The research was conducted as a case study and conceptually framed by institutional ethnography and critical geography. Methods included interviews, mental sketch mapping, and document analysis. The combination of methods was entirely qualitative and framed from a constructivist lens. Mental sketch mapping led to reflective spatial narratives that uncovered the ways that part-time faculty influenced and were influenced by spaces. Findings included the limited spaces participants utilized and felt comfortable in at the college, the lengths that they went to support their students, the challenges and barriers faced in teaching and other work including poor classroom and office spaces, and the lack of inclusion, despite the institution's efforts. The ruling relations of the college were evident in individual interactions, uses of space, and institutional policies and processes

Cheek Tooth Morphology and Ancient Mitochondrial DNA of Late Pleistocene Horses from the Western Interior of North America: Implications for the Taxonomy of North American Late Pleistocene Equus

Horses were a dominant component of North American Pleistocene land mammal communities and their remains are well represented in the fossil record. Despite the abundant material available for study, there is still considerable disagreement over the number of species of Equus that inhabited the different regions of the continent and on their taxonomic nomenclature. In this study, we investigated cheek tooth morphology and ancient mtDNA of late Pleistocene Equus specimens from the Western Interior of North America, with the objective of clarifying the species that lived in this region prior to the end-Pleistocene extinction. Based on the morphological and molecular data analyzed, a caballine (Equus ferus) and a non-caballine (E. conversidens) species were identified from different localities across most of the Western Interior. A second non-caballine species (E. cedralensis) was recognized from southern localities based exclusively on the morphological analyses of the cheek teeth. Notably the separation into caballine and non-caballine species was observed in the Bayesian phylogenetic analysis of ancient mtDNA as well as in the geometric morphometric analyses of the upper and lower premolars. Teeth morphologically identified as E. conversidens that yielded ancient mtDNA fall within the New World stilt-legged clade recognized in previous studies and this is the name we apply to this group. Geographic variation in morphology in the caballine species is indicated by statistically different occlusal enamel patterns in the specimens from Bluefish Caves, Yukon Territory, relative to the specimens from the other geographic regions. Whether this represents ecomorphological variation and/or a certain degree of geographic and genetic isolation of these Arctic populations requires further study

Environmental cues received during development shape dendritic cell responses later in life.

Environmental signals mediated via the aryl hydrocarbon receptor (AHR) shape the developing immune system and influence immune function. Developmental exposure to AHR binding chemicals causes persistent changes in CD4+ and CD8+ T cell responses later in life, including dampened clonal expansion and differentiation during influenza A virus (IAV) infection. Naïve T cells require activation by dendritic cells (DCs), and AHR ligands modulate the function of DCs from adult organisms. Yet, the consequences of developmental AHR activation by exogenous ligands on DCs later in life has not been examined. We report here that early life activation of AHR durably reduces the ability of DC to activate naïve IAV-specific CD8+ T cells; however, activation of naïve CD4+ T cells was not impaired. Also, DCs from developmentally exposed offspring migrated more poorly than DCs from control dams in both in vivo and ex vivo assessments of DC migration. Conditional knockout mice, which lack Ahr in CD11c lineage cells, suggest that dampened DC emigration is intrinsic to DCs. Yet, levels of chemokine receptor 7 (CCR7), a key regulator of DC trafficking, were generally unaffected. Gene expression analyses reveal changes in Lrp1, Itgam, and Fcgr1 expression, and point to alterations in genes that regulate DC migration and antigen processing and presentation as being among pathways disrupted by inappropriate AHR signaling during development. These studies establish that AHR activation during development causes long-lasting changes to DCs, and provide new information regarding how early life environmental cues shape immune function later in life

Enamel hypoplasia and dental wear of North American late Pleistocene horses and bison: an assessment of nutritionally based extinction models

Approximately 50,000–11,000 years ago many species around the world became extinct or were extirpated at a continental scale. The causes of the late Pleistocene extinctions have been extensively debated and continue to be poorly understood. Several extinction models have been proposed, including two nutritionally based extinction models: the coevolutionary disequilibrium and mosaic-nutrient models. These models draw upon the individualistic response of plant species to climate change to present a plausible scenario in which nutritional stress is considered one of the primary causes for the late Pleistocene extinctions. In this study, we tested predictions of the coevolutionary disequilibrium and mosaic- nutrient extinction models through the study of dental wear and enamel hypoplasia of Equus and Bison from various North American localities. The analysis of the dental wear (microwear and mesowear) of the samples yielded results that are consistent with predictions established for the coevolutionary disequilibrium model, but not for the mosaic-nutrient model. These ungulate species show statistically different dental wear patterns (suggesting dietary resource partitioning) during preglacial and full-glacial time intervals, but not during the postglacial in accordance with predictions of the coevolutionary disequilibrium model. In addition to changes in diet, these ungulates, specifically the equid species, show increased levels of enamel hypoplasia during the postglacial, indicating higher levels of systemic stress, a result that is consistent with the models tested and with other climate-based extinction models. The extent to which the increase in systemic stress was detrimental to equid populations remains to be further investigated, but suggests that environmental changes during the late Pleistocene significantly impacted North American equids.Natural Sciences and Engineering Research Council (NSERC