1,401 research outputs found
A study of the relationship between a child's adjustment and achievement in grade one,
Thesis (Ed.M.)--Boston Universit
A survey of children's interests from grade IV through grade VIII in the fields of active recreation, entertainment, reading, school subjects, and vocations.
Thesis (Ed.M.)--Boston Universit
Expression of three GnRH receptors in specific tissues in male and female sea lampreys Petromyzon marinus at three distinct life stages
Two recently cloned gonadotropin-releasing hormone (GnRH) receptors (lamprey GnRH-R-2 and lamprey GnRH-R-3) along with lamprey (l) GnRH-R-1 were shown to share similar structural features and amino acid motifs common to other vertebrate receptors. Here we report on our findings of RNA expression of these three GnRH receptors in the three major life stages (larval, parasitic, and adult phases) of the sea lamprey, Petromyzon marinus, a basal vertebrate. For each stage, we examined the expression of messenger RNA encoding the receptors in the brain, pituitary, gonad, heart, muscle, liver, eye, intestine, kidney, skin, thyroid, gill, and endostyle by RT-PCR. In adult lampreys, the spatial expression of the three receptors in the brain and pituitary was investigated by in situ hybridization. In general, the receptors were more widely expressed in adult tissues as compared to parasitic-phase tissues and least widely expressed in the larval tissues. There were noted differences in male and female lampreys in the adult and parasitic phases for all three receptors. The data showed the presence of all three receptor transcripts in brain tissues for adult and parasitic phases and all three receptor transcripts were expressed in the adult pituitaries, but not in the parasitic pituitaries. However, in the larval phase, only lGnRH-R-1 was expressed in the larval brain and pituitary. In situ hybridization revealed that lGnRH-R-2 and -3 were expressed in the pineal tissue of adult female lampreys while lGnRH-R-1 was expressed in the pineal in adult male lampreys, all restricted to the pineal pellucida. In summary, these data provide an initial comparative analysis of expression of three lamprey GnRH receptors suggesting differential regulation within males and females at three different life/reproductive stages
Predictors of Depression for Low-Income African American Single Mothers
Purpose: To test a model of predictors of depression in low-income single African American mothers. Design: Secondary analysis of existing data collected as part of a study of women at risk for clinical depression.
Methods: Cross sectional secondary data analysis of a study of low-income African American single mothers with children ages 2-6. Path analysis was used to test a model of the potential mediating role of negative thinking. It was hypothesized that negative thinking mediates the effects of chronic stressors, general health status, and self-esteem on depressive symptoms
Finding: Negative thinking mediated the relationships of chronic stressors and self-esteem with depressive symptoms. Conclusions: These findings supported the proposed model with one exception: negative thinking did not mediate the effects of physical health on depressive symptoms. Physical health also had no direct effect on depressive symptoms. Negative thinking may play a pivotal role in the development of depression for these at risk women. Self-esteem, chronic stressors and negative thinking should be important considerations in designing interventions to improve the mental health of at-risk African American women
Synthetic Access to Ring-Expanded N-Heterocyclic Carbene (RE-NHC) Copper Complexes and their Performance in Click Chemistry
The facile syntheses of ring-expanded N-heterocyclic carbene (RE-NHC) copper(I) halide complexes are reported. The method makes use of a weak inorganic base in a green solvent. The reaction times can be greatly reduced by use of this weak-base route under microwave irradiation. The easy access to these complexes permits an evaluation of the catalytic activity and reaction profiling of [Cu(RE-NHC)X] complexes in the Huisgen 1,3-cycloaddition reaction
Development and Implementation of a Culturally Tailored, Community-Based Intervention to Raise Awareness of Brain Health Among African Americans
African Americans bear a disproportionate burden of age-related cognitive impairment in the United States compared to Whites or Hispanics. African Americans experience greater prevalence, higher risk, and lower rates of treatment and diagnosis for dementia. In response to these health disparities the Alzheimer’s Association developed and implemented the Healthy Brain Initiative (HBI) demonstration project, the first community-level intervention to help reduce health disparities related to cognitive impairment among African Americans. The HBI promotes awareness of brain health, understanding of the heart-brain connection, and seeks to increase African American baby boomers engagement in health-protective behaviors to promote brain and overall health. The intervention was developed and implemented following engagement of local chapters and expert advisors, extensive formative evaluation to test intervention concepts, messages and materials, research on theoretical approaches and intervention strategies, and development of the HBI program theory or logic model. The core elements of the intervention included development of strategic partnerships, conduct of knowledge and awareness building educational workshops, community events and use of local media to promote the intervention and recruit participants
Mapping quantitative trait loci (QTL) in sheep. IV. Analysis of lactation persistency and extended lactation traits in sheep
<p>Abstract</p> <p>Background</p> <p>In sheep dairy production, total lactation performance, and length of lactation of lactation are of economic significance. A more persistent lactation has been associated with improved udder health. An extended lactation is defined by a longer period of milkability. This study is the first investigation to examine the presence of quantitative trait loci (QTL) for extended lactation and lactation persistency in sheep.</p> <p>Methods</p> <p>An (Awassi Ă— Merino) Ă— Merino single-sire backcross family with 172 ewes was used to map QTL for lactation persistency and extended lactation traits on a framework map of 189 loci across all autosomes. The Wood model was fitted to data from multiple lactations to estimate parameters of ovine lactation curves, and these estimates were used to derive measures of lactation persistency and extended lactation traits of milk, protein, fat, lactose, useful yield, and somatic cell score. These derived traits were subjected to QTL analyses using maximum likelihood estimation and regression analysis.</p> <p>Results</p> <p>Overall, one highly significant (LOD > 3.0), four significant (2.0 < LOD < 3.0) and five suggestive (1.7 < LOD < 2.0) QTL were detected across all traits in common by both mapping methods. One additional suggestive QTL was identified using maximum likelihood estimation, and four suggestive (0.01 < P < 0.05) and two significant (P < 0.01) QTL using the regression approach only. All detected QTL had effect sizes in the range of 0.48 to 0.64 SD, corresponding to QTL heritabilities of 3.1 to 8.9%. The comparison of the detected QTL with results in cattle showed conserved linkage regions. Most of the QTL identified for lactation persistency and extended lactation did not coincide. This suggests that persistency and extended lactation for the same as well as different milk yield and component traits are not controlled by the same genes.</p> <p>Conclusion</p> <p>This study identified ten novel QTL for lactation persistency and extended lactation in sheep, but results suggest that lactation persistency and extended lactation do not have a major gene in common. These results provide a basis for further validation in extended families and other breeds as well as targeting regions for genome-wide association mapping using high-density SNP arrays.</p
Insights Developed Into the Damage Mechanism of Teflon FEP Thermal Control Material on the Hubble Space Telescope
Metalized Teflon FEP (DuPont; fluorinated ethylene propylene) thermal control material on the Hubble Space Telescope (HST) has been found to degrade in the space environment. Teflon FEP thermal control blankets retrieved during the first servicing mission were found to be embrittled on solar-facing surfaces and to contain microscopic cracks (the FEP surface is exposed to the space environment). During the second servicing mission, astronauts noticed that the FEP outer layer of the multilayer insulation blanketing covering the telescope was cracked in many locations. Large cracks were observed on the light shield, forward shell, and equipment bays. A tightly curled piece of cracked FEP from the light shield was retrieved during the second mission. This piece was severely embrittled, as witnessed by ground testing. A Failure Review Board was organized by NASA Goddard Space Flight Center to determine the mechanism causing the multilayer insulation degradation. This board included members of the Electro-Physics Branch of the NASA Glenn Research Center at Lewis Field. Density measurements of the retrieved materials obtained under the review board's investigations indicated that FEP from the first servicing mission was essentially unchanged from pristine FEP but that the second servicing mission FEP had increased in density in comparison to pristine FEP (ref. 1). The results were consistent with crystallinity measurements taken using x-ray diffraction and with results from solid-state nuclear magnetic resonance tests (see the table and ref. 1). Because the second servicing mission FEP was embrittled and its density and crystallinity had increased in comparison to pristine FEP, board researchers expected that the first servicing mission FEP, which was also embrittled, would also have increased in crystallinity and density, but it did not. Because the retrieved second servicing mission material curled while in space, it experienced a higher temperature extreme during thermal cycling (estimated at 200 C) than the first servicing mission material (estimated at 50 C). Therefore, Glenn initiated and conducted an investigation of the effects of heating pristine FEP and FEP that had been exposed on the Hubble Space Telescope. Samples of pristine and first and second servicing mission FEP were heated to 200 C and evaluated for changes in density and morphology. We hoped that the results would help explain why FEP degrades in the Hubble Space Telescope space environment
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High-throughput isolation and characterization of untagged membrane protein complexes: outer membrane complexes of Desulfovibrio vulgaris.
Cell membranes represent the "front line" of cellular defense and the interface between a cell and its environment. To determine the range of proteins and protein complexes that are present in the cell membranes of a target organism, we have utilized a "tagless" process for the system-wide isolation and identification of native membrane protein complexes. As an initial subject for study, we have chosen the Gram-negative sulfate-reducing bacterium Desulfovibrio vulgaris. With this tagless methodology, we have identified about two-thirds of the outer membrane- associated proteins anticipated. Approximately three-fourths of these appear to form homomeric complexes. Statistical and machine-learning methods used to analyze data compiled over multiple experiments revealed networks of additional protein-protein interactions providing insight into heteromeric contacts made between proteins across this region of the cell. Taken together, these results establish a D. vulgaris outer membrane protein data set that will be essential for the detection and characterization of environment-driven changes in the outer membrane proteome and in the modeling of stress response pathways. The workflow utilized here should be effective for the global characterization of membrane protein complexes in a wide range of organisms
On Black Hole Detection with the OWL/Airwatch Telescope
In scenarios with large extra dimensions and TeV scale gravity ultrahigh
energy neutrinos produce black holes in their interactions with the nucleons.
We show that ICECUBE and OWL may observe large number of black hole events and
provide valuable information about the fundamental Planck scale and the number
of extra dimensions. OWL is especially well suited to observe black hole events
produced by neutrinos from the interactions of cosmic rays with the 3 K
background radiation. Depending on the parameters of the scenario of large
extra dimensions and on the flux model, as many as 28 events per year are
expected for a Planck scale of 3 TeV.Comment: 8 pages, including 7 color figures, three figure captions corrected,
minor changes for clarification, one reference adde
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