325 research outputs found
Evaluation of Human Fecal Pollution in Mississippi Coastal and Creek Waters Using Library Independent Markers
The objective of this study was to determine whether statistically valid correlations could be elucidated between standard indicator bacteria (enterococci and fecal coliforms) from coastal creek and marine samples and the presence of four library independent molecular markers that are human or sewage specific. Eight hundred and nineteen samples were collected between August 2007 and July 2010 to determine enterococcal and fecal coliform counts and the presence of genetic markers for sewage indicator organisms Methanobrevibacter smithii, human specific Bacteroides sp., Bacteroides thetaiotaomicron, and Fecalibacterium sp. During the course of this study environmental parameters were measured and statistically analyzed to determine if there was any correlation for the presence of any one of these organisms and the environmental variables
Using theories of action to ensure conceptual research use results in impactful research-informed interventions
Does a theory of action approach help teachers engage in evidence-informed self-improvement?
The purpose of this article is to evaluate how Theories of Action (TofA) can help teachers develop evidence informed teaching practices by providing a journey guide for impact and aid understanding of why an intervention works and which aspects of the approach drives change. This paper reports on a very specific approach - a partnership between an academic and three schools and is based on interviews with 15 teachers and school leaders, and pre and post intervention surveys relating to teachersâ use of research.The findings suggests that evidence informed practice, when aided by TofAâs can lead to substantial impact on teacher and pupil outcomes. By helping teachers consider how to tailor theories of action so interventions operate most effectively in their own settings this paper concludes that the effective scale up of research-informed interventions is to do with understanding why interventions have been successful and how that success might be realised in a new context.This article reports on how using Theories of Action (TofA) can help teachers scale-up evidence-informed teaching practices by aiding their understanding of why such interventions have been effective and which aspects are key to driving change. This paper reports on a specific approach: a partnership between an academic and three schools. The findings, based on interviews with 15 teachers and school leaders, and pre and post intervention surveys suggests that the scale-up of evidence-informed practice, when aided by TofAâs can lead to substantial impact on teacher and pupil outcomes. The paper concludes that the effective scale up of evidence-informed interventions is grounded in teachersâ understanding of why interventions have been successful and how that success might be realised in a new context. Correspondingly when teachers are shown how to use TofAs to tailor interventions, this helps them ascertain how such interventions can be realised most effectively in their own settings.<br/
CSAC Flight Experiment to Characterize On-Orbit Performance
Precise positioning, navigation, and timing requirements are driving a need for increasingly accurate spacecraft timing systems. This paper describes an experiment being developed at the University of Colorado Boulder to quantify the stability and behavior of a chip-scale atomic clock (CSAC) onboard an Air Force Research Laboratory (AFRL) University Nanosatellite Program (UNP-9) MAXWELL CubeSat mission. The CSAC experiment will run onboard MAXWELL, enabling the GPS receiver measurements to occur using the unsteered CSAC as an external clock. The experiment will record and downlink the position, clock bias, pseudorange, phase, and temperature. These data will allow us to characterize the on-orbit performance of the CSAC
Pinpointing The Extent Of Electronic Delocalization In The Re(i)-to-tetrazine Charge-separated Excited State Using Time-resolved Infrared Spectroscopy
Femtosecond mid-IR transient absorption spectroscopy (TRIR) and time-dependent density functional theory (TD-DFT) calculations on Re(CO)(3)Cl(Me(2)BPTZ) [Me(2)BPTZ = 3,6-bis(5-methyl-2-pyridine)-1,2,4,5-tetrazine] are used to demonstrate that the lowest excited state of the complex is a triplet metal-to-ligand charge-transfer ((3)MLCT) state with a lifetime of 225 ps. The short excited-state lifetime is explained by the energy-gap taw. Vibrational cooling of the (3)MLCT state shows up as early-time dynamics (3.6 ps). The structural changes in the excited state are deduced from the frequency shifts in the TRIR vibrational bands. The vibrational frequencies of the CO groups increase upon excitation as a result of decreased back-bonding between the CO ligands and the oxidized Re center in the (3)MLCT state. The vibrational frequencies of the central tetrazine ring of Me(2)BPTZ decrease because of the decrease in the bond order upon reduction of the Me(2)BPTZ ligand in the (3)MLCT state. Interestingly, the TRIR signals from the pyridine moieties of Me2BPTZ were not detected. These results can be explained by localization of the electronic charge on the central tetrazine ring in the (3)MLCT state of Re(CO)(3)Cl(Me(2)BPTZ), as supported by TD-DFT calculations
DISC1âATF4 transcriptional repression complex: dual regulation of the cAMP-PDE4 cascade by DISC1
Disrupted-In-Schizophrenia 1 (DISC1), a risk factor for major mental illnesses, has been studied extensively in the context of neurodevelopment. However, the role of DISC1 in neuronal signaling, particularly in conjunction with intracellular cascades that occur in response to dopamine, a neurotransmitter implicated in numerous psychiatric disorders, remains elusive. Previous data suggest that DISC1 interacts with numerous proteins that impact neuronal function, including activating transcription factor 4 (ATF4). In this study, we identify a novel DISC1 and ATF4 binding region in the genomic locus of phosphodiesterase 4D (PDE4D), a gene implicated in psychiatric disorders. We found that the loss of function of either DISC1 or ATF4 increases PDE4D9 transcription, and that the association of DISC1 with the PDE4D9 locus requires ATF4. We also show that PDE4D9 is increased by D1-type dopamine receptor dopaminergic stimulation. We demonstrate that the mechanism for this increase is due to DISC1 dissociation from the PDE4D locus in mouse brain. We further characterize the interaction of DISC1 with ATF4 to show that it is regulated via protein kinase A-mediated phosphorylation of DISC1 serine-58. Our results suggest that the release of DISC1-mediated transcriptional repression of PDE4D9 acts as feedback inhibition to regulate dopaminergic signaling. Furthermore, as DISC1 loss-of-function leads to a specific increase in PDE4D9, PDE4D9 itself may represent an attractive target for therapeutic approaches in psychiatric disorders.National Institute of General Medical Sciences (U.S.) (Award T32GM07753)National Institutes of Health (U.S.) (R01 MH091115
Changes in skeletal muscle and tendon structure and function following genetic inactivation of myostatin in rats
Myostatin is a negative regulator of skeletal muscle and tendon mass. Myostatin deficiency has been well studied in mice, but limited data are available on how myostatin regulates the structure and function of muscles and tendons of larger animals. We hypothesized that, in comparison to wildâtype (MSTN+/+) rats, rats in which zinc finger nucleases were used to genetically inactivate myostatin (MSTNÎ/Î) would exhibit an increase in muscle mass and total force production, a reduction in specific force, an accumulation of type II fibres and a decrease and stiffening of connective tissue. Overall, the muscle and tendon phenotype of myostatinâdeficient rats was markedly different from that of myostatinâdeficient mice, which have impaired contractility and pathological changes to fibres and their extracellular matrix. Extensor digitorum longus and soleus muscles of MSTNÎ/Î rats demonstrated 20â33% increases in mass, 35â45% increases in fibre number, 20â57% increases in isometric force and no differences in specific force. The insulinâlike growth factorâ1 pathway was activated to a greater extent in MSTNÎ/Î muscles, but no substantial differences in atrophyârelated genes were observed. Tendons of MSTNÎ/Î rats had a 20% reduction in peak strain, with no differences in mass, peak stress or stiffness. The general morphology and gene expression patterns were similar between tendons of both genotypes. This large rodent model of myostatin deficiency did not have the negative consequences to muscle fibres and extracellular matrix observed in mouse models, and suggests that the greatest impact of myostatin in the regulation of muscle mass may not be to induce atrophy directly, but rather to block hypertrophy signalling.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111244/1/tjp6572.pd
Prostaglandin E2 released from activated microglia enhances astrocyte proliferation in vitro
Microglial activation has been implicated in many astrogliosis-related pathological conditions including astroglioma; however, the detailed mechanism is not clear. In this study, we used primary enriched microglia and astrocytes cultures to determine the role of microglial prostaglandin E2 (PGE2) in the proliferation of astrocytes. The proliferation of astrocytes was measured by BrdU incorporation. The level of PGE2 was measured by ELISA method. Pharmacological inhibition or genetic ablation of COX-2 in microglia were also applied in this study. We found that proliferation of astrocytes increased following lipopolysaccharide (LPS) treatment in the presence of microglia. Furthermore, increased proliferation of astrocytes was observed in the presence of conditioned media from LPS-treated microglia. The potential involvement of microglial PGE2 in enhanced astrocyte proliferation was suggested by the findings that PGE2 production and COX-2 expression in microglia were increased by LPS treatment. In addition, activated microglia-induced increases in astrocyte proliferation were blocked by the PGE2 antagonist AH6809, COX-2 selective inhibitor DuP-697 or by genetic knockout of microglial COX-2. These findings were further supported by the finding that addition of PGE2 to the media significantly induced astrocyte proliferation. These results indicate that microglial PGE2 plays an important role in astrocyte proliferation, identifying PGE2 as a key neuroinflammatory molecule that triggers the pathological response related to uncontrollable astrocyte proliferation. These findings are important in elucidating the role of activated microglia and PGE2 in astrocyte proliferation and in suggesting a potential avenue in the use of anti-inflammatory agents for the therapy of astroglioma
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Integrated Reconnaissance of the Physical and Biogeochemical Characteristics of Jamaica Bay
Researchers at The Earth Institute of Columbia University have carried out an integrated, coordinated pilot reconnaissance of the physical, chemical, geological, and biological systems within Jamaica Bay, entitled "Integrated Reconnaissance of the Physical and Biogeochemical Characteristics of Jamaica Bay." We believe that such an integrated approach is necessary to fully understand the complex inter-relationship of the wetland ecosystem. The program focused on obtaining a synergistic view of the varied elements of Jamaica Bay by carrying out coordinated research in four areas: submarine sediment morphology, sediment and soil sampling, circulation and mixing, and chemical analysis of the Bay waters
Surveillance for Unexplained Deaths and Critical Illnesses
Population-based surveillance for unexplained death and critical illness possibly due to infectious causes (UNEX) was conducted in four U.S. Emerging Infections Program sites (population 7.7 million) from May 1, 1995, to December 31, 1998, to define the incidence, epidemiologic features, and etiology of this syndrome. A case was defined as death or critical illness in a hospitalized, previously healthy person, 1 to 49 years of age, with infection hallmarks but no cause identified after routine testing. A total of 137 cases were identified (incidence rate 0.5 per 100,000 per year). Patientsâ median age was 20 years, 72 (53%) were female, 112 (82%) were white, and 41 (30%) died. The most common clinical presentations were neurologic (29%), respiratory (27%), and cardiac (21%). Infectious causes were identified for 34 cases (28% of the 122 cases with clinical specimens); 23 (68%) were diagnosed by reference serologic tests, and 11 (32%) by polymerase chain reaction-based methods. The UNEX network model would improve U.S. diagnostic capacities and preparedness for emerging infections
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