425 research outputs found
Snail family genes disrupt cell death and are required for stem cell maintenance in the Drosophila melanogaster ovary
Cell death is an integral part of oogenesis in the fruit fly, Drosophila melanogaster. When the fly is starved of protein, some pre-vitellogenic egg chambers die apoptotically. As egg chambers mature, excess germline cells die via a non-apoptotic, developmentally programmed death. Overexpression of the transcription factor escargot was found to block both death events in the ovary, which is very unusual. escargot overexpression blocked starvation-dependent death upstream of caspases, but still needed a death signal to produce undead egg chambers. In maturing egg chambers, escargot overexpression blocked death more effectively than disrupting both apoptosis and autophagy, indicating that it must affect non-apoptotic, non-autophagic death mechanisms. RNA-Seq and a genetic modifier screen were used to identify potential escargot targets that inhibit cell death. Studies were also undertaken to characterize the loss-of-function phenotype of escargot in the ovary.
escargot is a member of the Snail family of transcription factors that play integral roles in development and gene regulation throughout Bilaterian organisms. In Drosophila melanogaster, the genes snail, escargot, and worniu are critical for stem cells in neuroblasts, gut, and testis, but a role in the ovary had not been shown. To analyze Snail family function in the ovary, I made a triple deficiency that removed the three Snail family members, called ΔSF. Surprisingly, ΔSF homozygous follicle stem cells are rapidly lost. Follicle stem cell loss was rescued by the expression of escargot or worniu but not snail, indicating that there is shared capability between genes. Moreover, follicle stem cells did not linger in the germarium, and their loss was not prevented by blocking apoptosis, indicating that the ΔSF defect is a failure of stem cell maintenance. Together, the results described in this dissertation show that Snail genes are needed for the normal function of the Drosophila ovary, and that escargot can regulate multiple kinds of cell death. Understanding Snail family genes is particularly important for the study of cancer, as they are implicated in mechanisms underlying the cancer stem cell state. Analysis of the highly conserved Snail family genes in Drosophila illuminates their function and dysfunction in human health and disease
Sulfur and oxygen isotope characterization of an Eocene playa deposit, northern High Plains, and rainwater sulfate, Baton Rouge, USA
This thesis is composed of two independent chapters which are linked through the application of multiple stable isotope measurements of sulfate. Chapter 1 compares two Cenozoic playa deposits in the northern High Plains. Anomalous playa sulfate was discovered at Scotts Bluff which is speculated to have originated via the oxidation of volcanically emitted reduced sulfur gases. A question arises, then, is a volcanic origin of sulfate common for other Cenozoic playa deposits in the region. A complete stable isotope characterization was performed on the gypsum sulfate collected at Wolf Butte (nearby apparent playa setting) to determine if the sulfate has a similar origin to that in the Scotts Bluff playa. No17O anomaly was found in the sulfate at Wolf Butte and the δ34S values range from +12.2 to +14.8‰. Potential sources of sulfate at Wolf Butte include weathering of Cretaceous shale and leaching of volcanic ashes. It is concluded that Scotts Bluff and Wolf Butte represent two different playa gypsum deposits that existed during the Cenozoic in the High Plains. Chapter 2 looks into atmospheric chemical reactions that form tropospheric sulfate in Baton Rouge area. Multiple stable isotope compositions of atmospheric sulfate in La Jolla, California (Lee 2001) revealed competing oxidation pathways exist between ozone (O3) and hydrogen peroxide (H2O2). To elucidate the source and origin of atmospheric sulfate in Baton Rouge air shed, oxygen and sulfur isotopic compositions were analyzed. The outcome of this survey found that the sulfate isotopic composition data range from 0.25 to 1.43‰ and 11.8 to 19.3‰ for ∆17O and δ18O, respectively, and -1.4 to 3.8‰ for δ34S. High ∆17O values were not favored in the winter season as was seen in the study preformed in California (Lee 2001). The sulfate δ34S appear to be slightly depleted with respect to those in La Jolla rainwater and may be due to a predominately anthropogenic (δ34S~0‰) rather than marine (δ34S~+9.9‰ ±6‰) source of sulfate. Also, sulfate concentrations in rainwater were more than twice that measured in two nearby Louisiana monitoring stations, which may be due to the sampling site’s close proximity to oil refinery facilities
Zine: Police Sexual Violence
Social Justice Zines
Topic: Police Violence Targeting Black Women and Girls
Subtopics Include: gender- and sexuality-specific police violence, with a focus on Black trans women; the histories of violence against Black women; policing (dis)ability; and the relevance of intersectional identitieshttps://www.exhibit.xavier.edu/state_sanctioned_violence/1020/thumbnail.jp
Emotions and Casual Teachers: Implications of the Precariat for Initial Teacher Education.
It is the norm for the casual teaching precariat to experience insecure labour conditions requiring an additional skill set to teachers with stable employment. As more beginning teachers than ever before commence work in casual employment – often a tenuous and unsupported transition into the profession - it is beholden on teacher educators to re-think aspects of their preparation. Four teacher educators undertook ‘memory work’ based on their previous experiences as casual teachers. Content analysis of follow up focus group discussions stressed the emotional and challenging nature of casual teaching, for both novice and experienced teachers. Findings from this small study, as well as previous research on casual beginning teachers and casual teachers, provide significant insights that have ramifications for initial teacher education, highlighting the importance of the emotional practices of teachers
Psychology
Psychology is designed to meet scope and sequence requirements for the single-semester introduction to psychology course. The book offers a comprehensive treatment of core concepts, grounded in both classic studies and current and emerging research. The text also includes coverage of the DSM-5 in examinations of psychological disorders. Psychology incorporates discussions that reflect the diversity within the discipline, as well as the diversity of cultures and communities across the globe.https://commons.erau.edu/oer-textbook/1000/thumbnail.jp
The PIG‐A gene mutation assay in human biomonitoring and disease
The blood cell phosphatidylinositol glycan class A (PIG-A) gene mutation assay has been extensively researched in rodents for in vivo mutagenicity testing and is now being investigated in humans. The PIG-A gene is involved in glycosyl phosphatidylinositol (GPI)-anchor biosynthesis. A single mutation in this X-linked gene can lead to loss of membrane-bound GPI anchors, which can be enumerated via corresponding GPI-anchored proteins (e.g., CD55) using flow cytometry. The studies published to date by different research groups demonstrate a remarkable consistency in PIG-A mutant frequencies. Moreover, with the low background level of mutant erythrocytes in healthy subjects (2.9–5.56 × 10−6 mutants), induction of mutation post genotoxic exposure can be detected. Cigarette smoking, radiotherapy, and occupational exposures, including lead, have been shown to increase mutant levels. Future applications of this test include identifying new harmful agents and establishing new exposure limits. This mutational monitoring approach may also identify individuals at higher risk of cancer development. In addition, identifying protective agents that could mitigate these effects may reduce baseline somatic mutation levels and such behaviors can be encouraged. Further technological progress is required including establishing underlying mechanisms of GPI anchor loss, protocol standardization, and the development of cryopreservation methods to improve GPI-anchor stability over time. If successful, this assay has the potential be widely employed, for example, in rural and low-income countries. Here, we review the current literature on PIG-A mutation in humans and discuss the potential role of this assay in human biomonitoring and disease detection
The passage of the bomb radiocarbon pulse into the Pacific Ocean
Author Posting. © Arizona Board of Regents on behalf of the University of Arizona, 2010. This article is posted here by permission of Dept. of Geosciences, University of Arizona for personal use, not for redistribution. The definitive version was published in Radiocarbon 52 (2010): 1182-1190.We report and compare radiocarbon observations made on 2 meridional oceanographic sections along 150°W
in the South Pacific in 1991 and 2005. The distributions reflect the progressive penetration of nuclear weapons-produced 14C
into the oceanic thermocline. The changes over the 14 yr between occupations are demonstrably large relative to any possible
drift in our analytical standardization. The computed difference field based on the gridded data in the upper 1600 m of the section
exhibits a significant decrease over time (approaching 40 to 50‰ in Δ14C) in the upper 200–300 m, consistent with the
decadal post-bomb decline in atmospheric 14C levels. A strong positive anomaly (increase with time), centered on the low
salinity core of the Antarctic Intermediate Water (AAIW), approaches 50–60‰ in Δ14C, a clear signature of the downstream
evolution of the 14C transient in this water mass. We use this observation to estimate the transit time of AAIW from its “source
region” in the southeast South Pacific and to compute the effective reservoir age of this water mass. The 2 sections show small
but significant changes in the abyssal 14C distributions. Between 1991 and 2005, Δ14C has increased by 9‰ below 2000 m
north of 55°S. This change is accompanied overall by a modest increase in salinity and dissolved oxygen, as well as a slight
decrease in dissolved silica. Such changes are indicative of greater ventilation. Calculation of “phosphate star” also indicates
that this may be due to a shift from the Southern Ocean toward North Atlantic Deep Water as the ventilation source of the
abyssal South Pacific.This work was performed under National Science Foundation Grant number OCE-0223434 as well
as a cooperative agreement with NSF (most recently OCE-0228996)
The Value of Balanced Growth for Transportation
The Ohio Balanced Growth Program is a voluntary, locally-driven, incentive-driven program which aims to encourage compact, nodal development patterns. The Ohio Department of Transportation provided support for this research to evaluate potential links between Balanced Growth-type policy, land use and development patterns, and transportation benefits.
A literature review was completed to understand the existing body of knowledge regarding the connection between policy, land use, and transportation. This included a scan of Balanced Growth-type programs across the US. Twenty-six US Metropolitan Statistical Areas (MSAs) were selected and reviewed for general geographic and policy characteristics. Land use and transportation outcome data were examined via scatterplot and linear regression across all of the MSAs. The results were evaluated broadly in light of policy frameworks in effect in each MSA, by categorizing land use policy into “tiers” based on voluntary vs. mandatory provisions, and applicability to private and public investment. Finally, a policy review was completed to understand the potential benefits of policy change at the state, regional, and local agency levels.
Significant relationships were found between land use patterns, measured in terms of a sprawl composite index, and transportation outcomes for freeway lane miles, hours of delay, vehicle miles traveled, emissions, and safety. MSAs with “Tier 3” policies (mandatory, rigorous policy affecting both public and private investment) clustered together on both axes (transportation outcomes and sprawl); and MSAs within states clustered together along the sprawl score axis. Otherwise, there was no apparent pattern in the location of policy tiers along either the transportation or land use axes. Possible alternative explanations that could be evaluated in the future include overall transportation investment levels; inter-state and inter-regional travel demand; size and shape of the MSA; and market, economic and social factors. Conclusions included policy recommendations for ODOT in supporting compact, nodal development at the local, regional and state levels. Future study recommendations include pursuing future data collection, monitoring and evaluation over time
The Value of Balanced Growth for Transportation
The Ohio Balanced Growth Program is a voluntary, locally-driven, incentive-driven program which aims to encourage compact, nodal development patterns. The Ohio Department of Transportation provided support for this research to evaluate potential links between Balanced Growth-type policy, land use and development patterns, and transportation benefits.
A literature review was completed to understand the existing body of knowledge regarding the connection between policy, land use, and transportation. This included a scan of Balanced Growth-type programs across the US. Twenty-six US Metropolitan Statistical Areas (MSAs) were selected and reviewed for general geographic and policy characteristics. Land use and transportation outcome data were examined via scatterplot and linear regression across all of the MSAs. The results were evaluated broadly in light of policy frameworks in effect in each MSA, by categorizing land use policy into “tiers” based on voluntary vs. mandatory provisions, and applicability to private and public investment. Finally, a policy review was completed to understand the potential benefits of policy change at the state, regional, and local agency levels.
Significant relationships were found between land use patterns, measured in terms of a sprawl composite index, and transportation outcomes for freeway lane miles, hours of delay, vehicle miles traveled, emissions, and safety. MSAs with “Tier 3” policies (mandatory, rigorous policy affecting both public and private investment) clustered together on both axes (transportation outcomes and sprawl); and MSAs within states clustered together along the sprawl score axis. Otherwise, there was no apparent pattern in the location of policy tiers along either the transportation or land use axes. Possible alternative explanations that could be evaluated in the future include overall transportation investment levels; inter-state and inter-regional travel demand; size and shape of the MSA; and market, economic and social factors. Conclusions included policy recommendations for ODOT in supporting compact, nodal development at the local, regional and state levels. Future study recommendations include pursuing future data collection, monitoring and evaluation over time
The Value of Balanced Growth for Transportation: Executive Summary
This project evaluates the benefit that programs like the Ohio Balanced Growth Program could bring to transportation agencies in Ohio
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