4,152 research outputs found
Carbonate deposition, Pyramid Lake subbasin, Nevada: 2. Lake levels and polar jet stream positions reconstructed from radiocarbon ages and elevations of carbonates (tufas) deposited in the Lahontan basin
Most of the tufas in the Pyramid Lake subbasin were deposited within the last 35,000 yr, including most of the mound tufas that border the existing lake. Many of the older tufas (\u3e 21,000 yr B.P.) contained in the mounds were formed in association with ground-water discharge. The radiocarbon (14C) ages of the older tufas represent maximum estimates of the time of their formation. Lake Lahontan experienced large and abrupt rises in level at ~ 22,000, 15,000, and 11,000 yr B.P. and three abrupt recessions in level at ~ 16,000, 13,600, and 10,000 yr B.P. The lake-level rises that were initiated at ~23,500 and 15,500 yr B.P. are believed to indicate the passage of the polar jet stream over the Lahontan basin. During expansion of the Laurentide Ice Sheet, the jet stream moved south across the basin, and during the contraction of the Ice Sheet, the jet stream moved north across the basin.
The bulk of the carbonate contained in the mound tufas was deposited during the last major lake cycle (~23,500-12,000 yr B.P.), indicating that ground- and surface-water discharges increased at ~23,500 and decreased at ~ 12,000 yr B.P. A lake-level oscillation that occurred between 11,000 and 10,000 yr B.P. is represented by a 2-cm thick layer of dense laminated tufa that occurs at and below 1180 m in the low-elevation tufa mounds and at 1205 m in the Winnemucca Lake subbasin
Tundra Rodents in a Late Pleistocene Fauna from the Tofty Placer District, Central Alaska
Describes remains of the arctic ground squirrel, collared and brown lemmings, and the narrow-skulled vole collected 1956-1961 in or near the Sullivan mining pit. Topography, vegetation, and mining history are outlined, as are the stratigraphy and age of the unconsolidated deposits in which the fossils were found. The rodents, all typical tundra forms, are not now in the Tofty area which has been forested at least 6800 yr. Apparently, they represent the fauna of a colder climatic period during Wisconsin time
Nicholas Meyer: 10-31-1979
Nicholas Meyer is a screenwriter, producer, director, and author, and a graduate of the University of Iowa. He is the author of the screenplay the Seven Per Cent Solution and co-author of The Black Orchid. He begins the interview by discussing his professional career as both a film writer/director and a novelist. He then talks about how he began writing novels, and discusses the research that goes into his novels. Meyer continues by discussing his movie Time After Time and concludes the interview by listing prominent teachers and writing influences.https://digitalcommons.brockport.edu/writers_videos/1022/thumbnail.jp
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Coordenadores do TĂtulo IX como burocratas de nĂvel de rua nas escolas dos Estados Unidos: Desafios para enfrentar a discriminação sexual na era #MeToo
Sex discrimination in educational contexts is an ongoing problem despite the passage of Title IX in 1972. Many schools have not aligned their policies with new laws protecting students from bullying and harassment, and many professionals are unaware of their new obligations in regards to new state regulations. This article presents the findings from semi-structured interviews with 10 participants reporting on the roles and responsibilities of Title IX coordinators in their K-12 school districts. Title IX coordinators were difficult to locate and recruitment was a challenge in this study. However, our findings indicate a strong alignment with Lipsky’s concept of “street-level bureaucrats” (1971, 2010). We found that these school administrators had autonomy and discretion in interpreting and enacting their duties, however they lacked time, information, and other resources necessary to respond properly to the stated duties in their position. They reported spending very little time on Title IX-related duties, many felt under-supported and under-prepared, and few had comprehensive understanding of their responsibilities. We conclude with recommendations for policy and practice regarding the training and supports of Title IX coordinators and related gender equity efforts in K-12 schools.La discriminaciĂłn sexual en contextos educativos es un problema continuo a pesar de la aprobaciĂłn del TĂtulo IX en 1972. Muchas escuelas no han alineado sus polĂticas con nuevas leyes que protegen a los estudiantes de la intimidaciĂłn y el acoso, y muchos profesionales desconocen sus nuevas obligaciones con respecto a regulaciones estatales Este artĂculo presenta los hallazgos de entrevistas semiestructuradas con 10 participantes que informan sobre los roles y responsabilidades de los coordinadores del TĂtulo IX en sus distritos escolares K-12. Los coordinadores del TĂtulo IX fueron difĂciles de localizar y el reclutamiento fue un desafĂo en este estudio. Sin embargo, nuestros hallazgos indican una fuerte alineaciĂłn con el concepto de Lipsky de "burĂłcratas a nivel de calle" (1971, 2010). Descubrimos que estos administradores escolares tenĂan autonomĂa y discreciĂłn para interpretar y cumplir sus deberes, sin embargo, carecĂan de tiempo, informaciĂłn y otros recursos necesarios para responder adecuadamente a los deberes establecidos en su puesto. Informaron que dedicaron muy poco tiempo a los deberes relacionados con el TĂtulo IX, muchos se sintieron insuficientemente apoyados y poco preparados, y pocos tenĂan una comprensiĂłn exhaustiva de sus responsabilidades. Concluimos con recomendaciones de polĂticas y prácticas con respecto a la capacitaciĂłn y el apoyo de los coordinadores del TĂtulo IX y los esfuerzos relacionados con la equidad de gĂ©nero en las escuelas K-12.A discriminação sexual em ambientes educacionais Ă© um problema contĂnuo, apesar da aprovação do TĂtulo IX em 1972. Muitas escolas nĂŁo alinharam suas polĂticas com novas leis que protegem os alunos de intimidação e assĂ©dio, e muitos profissionais desconhecem seus direitos. novas obrigações com relação aos regulamentos estaduais Este artigo apresenta os resultados de entrevistas semi-estruturadas com 10 participantes que relatam os papĂ©is e responsabilidades dos coordenadores do TĂtulo IX em seus distritos escolares K-12. Os coordenadores do TĂtulo IX foram difĂceis de localizar e o recrutamento foi um desafio neste estudo. No entanto, nossos resultados indicam um forte alinhamento com o conceito de "burocratas de rua" de Lipsky (1971, 2010). Descobrimos que esses administradores escolares tinham autonomia e discrição para interpretar e cumprir suas obrigações, no entanto, eles nĂŁo tinham tempo, informações e outros recursos necessários para responder adequadamente aos deveres estabelecidos em sua posição. Eles relataram que gastaram muito pouco tempo em tarefas relacionadas ao TĂtulo IX, muitos se sentiram insuficientemente apoiados e despreparados, e poucos tinham uma compreensĂŁo abrangente de suas responsabilidades. ConcluĂmos com recomendações e práticas de polĂticas relacionadas Ă formação e apoio de coordenadores do TĂtulo IX e esforços relacionados Ă eqĂĽidade de gĂŞnero nas escolas do ensino fundamental e mĂ©dio
Epigenetic Plasticity Drives Adipogenic and Osteogenic Differentiation of Marrow-derived Mesenchymal Stem Cells
Terminal differentiation of multipotent stem cells is achieved through a coordinated cascade of activated transcription factors and epigenetic modifications that drive gene transcription responsible for unique cell fate. Within the mesenchymal lineage, factors such as RUNX2 and PPARγ are indispensable for osteogenesis and adipogenesis, respectively. We therefore investigated genomic binding of transcription factors and accompanying epigenetic modifications that occur during osteogenic and adipogenic differentiation of mouse bone marrow-derived mesenchymal stem cells (MSCs). As assessed by ChIP-sequencing and RNA-sequencing analyses, we found that genes vital for osteogenic identity were linked to RUNX2, C/EBPβ, retinoid X receptor, and vitamin D receptor binding sites, whereas adipocyte differentiation favored PPARγ, retinoid X receptor, C/EBPα, and C/EBPβ binding sites. Epigenetic marks were clear predictors of active differentiation loci as well as enhancer activities and selective gene expression. These marrow-derived MSCs displayed an epigenetic pattern that suggested a default preference for the osteogenic pathway; however, these patterns were rapidly altered near the Adipoq, Cidec, Fabp4, Lipe, Plin1, Pparg, and Cebpa genes during adipogenic differentiation. Surprisingly, we found that these cells also exhibited an epigenetic plasticity that enabled them to trans-differentiate from adipocytes to osteoblasts (and vice versa) after commitment, as assessed by staining, gene expression, and ChIP-quantitative PCR analysis. The osteogenic default pathway may be subverted during pathological conditions, leading to skeletal fragility and increased marrow adiposity during aging, estrogen deficiency, and skeletal unloading. Taken together, our data provide an increased mechanistic understanding of the epigenetic programs necessary for multipotent differentiation of MSCs that may prove beneficial in the development of therapeutic strategies
Clarifying Sound and Suspect Use of the Rorschach in Forensic Mental Health Evaluations:A Response to Areh et al. (2022)
EFFECTS OF INSULIN, GLUCAGON, AND INSULIN/GLUCAGON INFUSIONS ON LIVER MORPHOLOGY AND CELL DIVISION AFTER COMPLETE PORTACAVAL SHUNT IN DOGS
Insulin, glucagon, and insulin/glucagon mixtures have been infused for four days into the left portal vein of dogs after portacaval shunt. In the left but not the right liver lobes, insulin alone reduced atrophy, preserved hepatocyte ultrastructure, and trebled cell renewal. Glucagon alone had no effect. In small doses, glucagon did not potentiate the action of insulin and in large doses it may have reduced the insulin benefit. These studies explain the development of the previously mysterious Eck fistula syndrome, provide clues about in-vivo cell growth control by hormones, and suggest new lines of inquiry about the pathogenesis and/or treatment of several human disease processes. © 1976
Evolutionary Divergence of Duplicate Copies of the Growth Hormone Gene in Suckers (Actinopterygii: Catostomidae)
Catostomid fishes (suckers) have duplicate copies of the growth hormone gene and other nuclear genes, due to a genome duplication event early in the group’s history. Yet, paralogs of GH in suckers are more than 90% conserved in nucleotide (nt) and amino acid (aa) sequence. Within paralogs across species, variation in nt and aa sequence averages 3.33% and 4.46% for GHI, and 3.22% and 2.43% for GHII, respectively. Selection tests suggest that the two GH paralogs are under strong purifying selection. Consensus trees from phylogenetic analysis of GH coding region data for 23 species of suckers, other cypriniform fishes and outgroups resolved cypriniform relationships and relationships among GHI sequences of suckers more or less consistently with analyses based on other molecular data. However, the analysis failed to resolve all sucker GHI and GHII sequences as monophyletic sister groups. This unexpected topology did not differ significantly from topologies constrained to make all GH sequences monophyletic. We attribute this result either to limitations in our GHII data set or convergent adaptive changes in GHII of tribe Catostomini
Anisotropic ultrasonic backscatter from the renal cortex
We have demonstrated a significant, directionally dependent, anisotropic, echogenicity from the cortices of two sheep kidneys and a normal human cadaver kidney. The anisotropy corresponds to the relationship of the sound field to the medullary rays and interlobular arteries. At 7.5 MHz, the backscatter from specimens of cortex of a sheep kidney was 4.7 +/- .7 dB (mean +/- SEM) greater in parts of the cortex where the field was perpendicular to these structures as opposed to where it was parallel to them. In addition, we measured the angular distribution of this anisotropy and compared it to the 5 dB inclusion angle of the 5 MHz linear array that was used in measurements on the whole kidney specimens. The transducer inclusion angle was 10[deg] +/- 2[deg], while the angular distribution was 34[deg] +/- 22[deg] and 23[deg] +/- 11[deg] (mean +/- SD) for the intact sheep and human kidney, respectively, demonstrating some variation of the medullary rays from perfect specular reflectors. This anisotropy should be visible in standard diagnostic scanning, and its recognition could increase ultrasound's sensitivity for the detection of renal disease.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27571/1/0000615.pd
Infrared study of the Southern Galactic star forming region associated with IRAS 14416-5937
Aims: We have carried out an infrared study of the southern Galactic massive
star forming region associated with IRAS 14416-5937. Methods: This star forming
region has been mapped simultaneously in two far infrared bands at ~ 150 & 210
micron using the TIFR 1-m balloon borne telescope with ~ 1' angular resolution.
We have used 2MASS JHK as well as Spitzer-GLIMPSE data of this region to
study the stellar populations of the embedded young cluster. This region
comprises of two sources, designated as A & B and separated by ~ 2 pc. The
spectrum of a region located close to the source A obtained using the Long
Wavelength Spectrometer (LWS) on-board the Infrared Space Observatory (ISO), is
presented. Emission from warm dust and from Unidentified Infrared Bands (UIBs)
is estimated using the mid-infrared data of the MSX survey. Results: The
spatial distributions of (1) the temperature of cool dust and (2) optical depth
at 200 micron have been obtained taking advantage of the similar beams in both
the TIFR bands. A number of atomic fine structure lines have been detected in
the ISO-LWS spectrum, which have been used to estimate the electron density and
the effective temperature of the ionising radiation in this region. From the
near and mid infrared images, we identify a dust lane due north-west of source
A. The dust lane is populated by Class I type sources. Class II type sources
are found further along the dust lane as well as below it. Self consistent
radiative transfer models of the two sources (A and B) are in good agreement
with the observed spectral energy distributions. Conclusions: The spatial
distribution of young stellar objects in and around the dust lane suggests that
active star formation is taking place along the dust lane and is possibly
triggered by the expanding HII regions of A and B.Comment: Accepted by the Astronomy and Astrophysics (21 pages, 7 tables and 13
figures
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