4,548 research outputs found
An eighth-century inscribed cross-slab in Dull, Perthshire
The discovery of a cross-inscribed slab with an inscription is described. Because of its importance it was decided to invite specialist comment on this piece of sculpture and to publish it in advance of the full report on the excavations. The form of the monument, its inscription and archaeological context are considered. The text appears to consist of a Gaelic personal name. The script is a form of geometrical lettering which can be dated to the opening quarter of the eighth century. The form of the cross has Columban associations which sit well with place-name and other evidence which points to Dull having been a monastery founded from Iona by c. AD 700
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RNase P Branches Out from RNP to Protein: Organelle-Triggered Diversification?
RNase P is the enzyme that removes 5′ leader sequences from precursor tRNAs. Remarkably, in most organisms, RNase P is a ribonucleoprotein particle where the RNA component is responsible for catalysis. In this issue of Genes \u26 Development, Gutmann and colleagues (pp. 1022–1027) report the first organism,Arabidopsis thaliana, to employ protein-only RNase P in both its nucleus and organelles. An intriguing possibility is that replacement of RNase P ribonucleoprotein particles (RNPs) by proteins may have been triggered by the acquisition of organelles
Upregulation of the Coagulation Factor VII Gene during Glucose Deprivation Is Mediated by Activating Transcription Factor 4
Background: Constitutive production of blood coagulation proteins by hepatocytes is necessary for hemostasis. Stressful conditions trigger adaptive cellular responses and delay processing of most proteins, potentially affecting plasma levels of proteins secreted exclusively by hepatocytes. We examined the effect of glucose deprivation on expression of coagulation proteins by the human hepatoma cell line, HepG2. Methodology/Principal Findings: Expression of coagulation factor VII, which is required for initiation of blood coagulation, was elevated by glucose deprivation, while expression of other coagulation proteins decreased. Realtime PCR and ELISA demonstrated that the relative percentage expression +/− SD of steady-state F7 mRNA and secreted factor VII antigen were significantly increased (from 100+/−15% to 188+/−27% and 100+/−8.8% to 176.3+/−17.3% respectively, p<0.001) at 24 hr of treatment. The integrated stress response was induced, as indicated by upregulation of transcription factor ATF4 and of additional stress-responsive genes. Small interfering RNAs directed against ATF4 potently reduced basal F7 expression, and prevented F7 upregulation by glucose deprivation. The response of the endogenous F7 gene was replicated in reporter gene assays, which further indicated that ATF4 effects were mediated via interaction with an amino acid response element in the F7 promoter. Conclusions/Significance: Our data indicated that glucose deprivation enhanced F7 expression in a mechanism reliant on prior ATF4 upregulation primarily due to increased transcription from the ATF4 gene. Of five coagulation protein genes examined, only F7 was upregulated, suggesting that its functions may be important in a systemic response to glucose deprivation stress
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Dual Enrollment Programs: Easing Transitions from High School to College
Research demonstrates clear economic benefits for students who continue education beyond high school (NCES, 2001). Yet the transition from high school to college is an unsuccessful one for many. Of those high school graduates who entered postsecondary education for the first time in the 1995-1996 school year, 37 percent had left two years later without having earned a degree or certificate. This slippage results from a variety of causes. Some students are unsure how to apply for college or how to pay for it; some are academically unprepared for higher education; some face a frustrating task of balancing school and work. As postsecondary education becomes increasingly necessary to gain access to most reasonably well-paid jobs, the sharp division between high schools and colleges becomes more problematic
Effect of natural products on the production and activity of Clostridium difficile toxins in vitro
Clostridium difficile infection is a toxin-mediated disease of the colon. C. difficile virulence is primarily attributed to the production of toxin A and toxin B; thus this study was aimed to investigate the effect of a range of natural products on the production and activity of C. difficile toxins in vitro. Twenty-two natural products were investigated against four C. difficile strains. The activity of products against toxins was determined using Vero and HT-29 cells cytotoxicity and neutral red uptake assays. The indirect effect of products on toxin-mediated cytotoxicity was determined using the same cell lines. The effect of seven products on toxin production by C. difficile was determined using ELISA. Zingerone (0.3 mg/ml) protected both cell lines from C. difficile cytopathic effects, confirmed by the neutral red uptake assay (P \u3c 0.05). Three Leptospermum honeys (4% w/v), fresh onion bulb extract (12.5% v/v) and trans-cinnamaldehyde (0.005% v/v) all reduced toxin production and activity significantly (P ≤ 0.023). Garlic clove powder (4.7 mg/ml) only reduced toxin activity (P ≤ 0.047). Overall, several natural products had activity against C. difficile toxins in vitro encouraging further investigation against C. difficile toxins in vivo
Night-time lighting alters the composition of marine epifaunal communities
Marine benthic communities face multiple anthropogenic pressures that compromise the future of some of the most biodiverse and functionally important ecosystems in the world. Yet one of the pressures these ecosystems face, night-time lighting, remains unstudied. Light is an important cue in guiding the settlement of invertebrate larvae, and altering natural regimes of nocturnal illumination could modify patterns of recruitment among sessile epifauna. We present the first evidence of night-time lighting changing the composition of temperate epifaunal marine invertebrate communities. Illuminating settlement surfaces with white light-emitting diode lighting at night, to levels experienced by these communities locally, both inhibited and encouraged the colonization of 39% of the taxa analysed, including three sessile and two mobile species. Our results indicate that ecological light pollution from coastal development, shipping and offshore infrastructure could be changing the composition of marine epifaunal communities.European Research Council under the European Union's Seventh Framework programme (FP7/2007-2013
Difference in Structure and Electronic Properties of Oxygen Vacancies in α-Quartz and α-Cristobalite Phases of SiO2
α-cristobalite (α-C) is a polymorph of silica, mainly found in space exploration and geochemistry research. Due to similar densities, α-C is often used as a proxy for amorphous SiO2, particularly in computer simulations of SiO2 surfaces and interfaces. However, little is known about the properties of α-C and its basic oxygen defects. Using density functional theory (DFT) simulations we provide a comprehensive report on the properties of perfect structure and oxygen vacancies in α-C. The calculated properties of α-C are compared with those of the better-characterized α-quartz (α-Q). Our results demonstrated that the positively charged O vacancy in α-C is most stable in the dimer configuration, in contrast to α-Q, which favors the puckered configuration. A back-projected configuration was also predicted in both polymorphs. We calculated the optical transition energies and isotropic hyperfine constants for O vacancies in both α-Q and α-C, and compared our findings with the results of previous studies and experiments. This work, thus, offers one of the first in-depth investigations of the properties of oxygen vacancies in α-C
Treatment algorithm for infants diagnosed with spinal muscular atrophy through newborn screening
Spinal muscular atrophy (SMA) is an autosomal recessive disease characterized by the degeneration of alpha motor neurons in the spinal cord, leading to muscular atrophy. SMA is caused by deletions or mutations in the survival motor neuron 1 gene (SMN1). In humans, a nearly identical copy gene, SMN2, is present. Because SMN2 has been shown to decrease disease severity in a dose-dependent manner, SMN2 copy number is predictive of disease severity.
To develop a treatment algorithm for SMA-positive infants identified through newborn screening based upon SMN2 copy number.
A working group comprised of 15 SMA experts participated in a modified Delphi process, moderated by a neutral third-party expert, to develop treatment guidelines.
The overarching recommendation is that all infants with two or three copies of SMN2 should receive immediate treatment (n = 13). For those infants in which immediate treatment is not recommended, guidelines were developed that outline the timing and appropriate screens and tests to be used to determine the timing of treatment initiation.
The identification SMA affected infants via newborn screening presents an unprecedented opportunity for achievement of maximal therapeutic benefit through the administration of treatment pre-symptomatically. The recommendations provided here are intended to help formulate treatment guidelines for infants who test positive during the newborn screening process
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Institutionalization and Sustainability of the National Science Foundation's Advanced Technological Education program
This three-year study closely examined six ATE projects and four national centers. The analysis was specifically concerned with the ability of the ATE projects and centers to meet the program's goal of having a significant and permanent influence on the host colleges and on the system of science, technology, engineering, and mathematics education (STEM) in general. Thus, the report discusses (1) the institutionalization of the projects and centers--the extent to which their activities are becoming incorporated into the normal, ongoing activities of the host community colleges; and (2) their sustainability--the extent to which the major activities of the ATE program continue after the NSF grant expires. The report concludes that the ATE program has an impressive record of accomplishment, particularly in the influence it has had on curriculum and professional development, and on bringing together community colleges, universities, high schools, businesses, and other groups in a unique initiative to improve the education of our nation's STEM technicians
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