1,112 research outputs found
Biochemical Characterization of the Flavivirus-resistance Mouse ABCF3 Protein and a Review of the Antibiotic Resistance and Dissemination Mechanisms in Bacteria
Mammalian ATP-binding cassette subfamily F member 3 (ABCF3) is a class 2 ABC protein that has previously been identified as a partner of the mouse flavivirus resistance protein 2′,5′-oligoadenylate synthetase 1B (OAS1B). The functions and natural substrates of ABCF3 are currently not known. In Chapter 1 of this study, we show that purified ABCF3 is an active ATPase. Binding analyses with a fluorescent ATP analog TNP-ATP suggested unequal contributions by the two nucleotide-binding domains. We further showed that ABCF3 activity is increased by lipids, including sphingosine, sphingomyelin, platelet-activating factor, and lysophosphatidylcholine. However, cholesterol inhibited ABCF3 activity, whereas alkyl ether lipids either inhibited or resulted in a biphasic response, suggesting small changes in lipid structure differentially affect ABCF3 activity. Point mutations in the two nucleotide-binding domains of ABCF3 affected basal and sphingosine-stimulated ATPase activity differently, further supporting different roles for the two catalytic pockets. We propose a model in which pocket 1 is the site of basal catalysis, whereas pocket 2 engages in ligand-stimulated ATP hydrolysis. Co-localization of the ABCF3–OAS1B complex to the virus-remodeled endoplasmic reticulum membrane has been shown before. We show that co-expression of ABCF3 and OAS1B in bacteria alleviated growth inhibition caused by expression of OAS1B alone, and significantly enhanced OAS1B levels, indirectly showing interaction between these two proteins in bacterial cells. As viral RNA synthesis requires large amounts of ATP, we conclude that lipid-stimulated ATP hydrolysis may contribute to the reduction in viral RNA production characteristic of the flavivirus resistance phenotype.
Chapter 2 of this dissertation provides a comprehensive review of the major known antibiotic resistance mechanisms, including the function of ABC proteins, found in producer soil bacteria and discusses different horizontal gene transfer mechanisms that may play a role in the dissemination of resistance genes from producer and non-producer environmental bacteria to pathogenic bacteria in clinical settings. Many bacterial and eukaryotic ABC proteins are polyspecific in nature and are capable of transporting structurally diverse compounds, including drugs and lipids. These proteins are responsible for intrinsic or acquired multidrug resistance, which can also spread to pathogenic organisms through the horizontal transfer mechanisms discussed in this review
The Life Story of President Barack Obama: Using Critical Race Theory to Analyze Life Experience
Using Critical Race Theory (CRT) as a lens and interest convergence and color-blind ideology as foci to explore the life experience of President Barack Obama, this study provides a framework for using CRT as a lens for examining life experience
Race and Racism: A Critical Dialogue
This is a dialogue between Elizabeth Peterson, a black, female adult educator and Stephen Brookfield, a white male. The question was whether or not we could come together and engage in a critical dialogue about race and racism
Starting Well: Facilitating the Middle School Transition
School-based mental health programming is a viable intervention because it can provide evidenced-based-treatment (EBT) while avoiding the typical service barriers. In this study, 119 students (ages 10 to 12) were randomly assigned to participate in either a 24-session Coping Power Program (CPP) or a control group. Using the Behavior Assessment Scale for Children-2 (BASC-2), teachers reported significant improvements over time for all students (Attention Problems, Hyperactivity, Externalizing Problems, and Withdrawal, and Study Skills). However, teachers reported that students participating in the CPP showed significantly greater improvement than controls (Learning Problems, School Problems, Behavior Symptom Index, Social Skills, and Adaptive Skills). Effect sizes ranged from small (.19 for Withdrawal) to large (.76 for Adaptive Skills). Teacher reports showed greater improvement by the more experienced group leaders. Results validate the use of this EBT as a viable protocol. The improvement in both groups may suggest a spillover effect for untreated controls. The differential effect of group leader suggests that clinical experience may enhance EBT
Effectiveness of the Coping Power Program in Middle-school Children with Disruptive Behaviours and Hyperactivity Difficulties
The purpose of this article is to discuss the effectiveness of the Coping Power Program (CPP); an evidencebased treatment delivered in a group format to at-risk middle-school children. Initially, two groups were randomised and formed: an intervention group of 24 CPP sessions and a control group. All students were enrolled in public schools from two rural counties in the United States. Out of the 119 total participants 63 (37 male) were in the intervention and 56 (35 male) were in the control group. From the larger intervention group, a subset of students was identified as ‘significantly improved’. Using the Behavior Assessment Scale for Children-2 (BASC-2), a pre- and post-intervention measure showed that students with clinically significant hyperactivity and behavioural difficulties scores were the most sensitive to the group intervention
Utilizing the Lens of Critical Race Theory to Analyze Stories of Race
In this paper the authors analyze three personal stories of race using Critical Race Theory (CRT). The analysis reveals common themes which speak to the tragic impact of racism on the lives of African Americans
Above- and below-ground Litter Manipulation: Effect on Retention and Release of DOC, DON and DIN in the Sikfokut Forest, Hungary
The above- and below-ground litter from fallen foliage and root exudates and their decomposition has an impact on forest soil. The objective of this research project was to determine the effect of above- and below-ground litter manipulation on the retention and release of dissolved organic carbon (DOC), dissolved organic nitrogen (DON), nitrate and ammonium in the soil profile at 0-5 and 5-15 cm depths. The soils were obtained from a Long Term Ecological Research site in the Sikfokut Forest in Hungary. The site is a mature oak forest and the soil has no organic layer; the leaf litter sits directly on the A horizon. There are six treatments applied to the soil: doubling of annual leaf litter (DL), doubling of annual wood litter (DW), removal of annual leaf litter (NL), removal of roots (NR), removal of leaf and roots (NI) and control (C). Each plot is 7 x 7 m, and each soil sample taken was 15 x 15 cm square. A stock solution of leaf litter was added in different concentrations to soils from each treatment in a 50 mL centrifuge tube. Because I was investigating retention or release of carbon and nitrogen, I inverted the tube gently over a period of 2 hours prior to centrifugation and removal of supernatant. The supernatant solution was analyzed for DOC, DON, ammonium and nitrate to determine retention and release values for each dependant upon the different treatments.
The results of the study were interesting. Dissolved organic nitrogen was neither retained nor released in the 0-5 cm layer for any treatment yet nitrate, typically considered a mobile anion showed retention and release in this layer. In the 5-15 cm layer we had no retention or release of nitrate but dissolved organic nitrogen was retained and released between the solid and solution phases
Trehalose Is A Chemical Attractant In The Establishment Of Coral Symbiosis
Coral reefs have evolved with a crucial symbiosis between photosynthetic dinoflagellates (genus Symbiodinium) and their cnidarian hosts (Scleractinians). Most coral larvae take up Symbiodinium from their environment; however, the earliest steps in this process have been elusive. Here we demonstrate that the disaccharide trehalose may be an important signal from the symbiont to potential larval hosts. Symbiodinium freshly isolated from Fungia scutaria corals constantly released trehalose (but not sucrose, maltose or glucose) into seawater, and released glycerol only in the presence of coral tissue. Spawning Fungia adults increased symbiont number in their immediate area by excreting pellets of Symbiodinium, and when these naturally discharged Symbiodinium were cultured, they also released trehalose. In Y-maze experiments, coral larvae demonstrated chemoattractant and feeding behaviors only towards a chamber with trehalose or glycerol. Concomitantly, coral larvae and adult tissue, but not symbionts, had significant trehalase enzymatic activities, suggesting the capacity to utilize trehalose. Trehalase activity was developmentally regulated in F. scutaria larvae, rising as the time for symbiont uptake occurs. Consistent with the enzymatic assays, gene finding demonstrated the presence of a trehalase enzyme in the genome of a related coral, Acropora digitifera, and a likely trehalase in the transcriptome of F. scutaria. Taken together, these data suggest that adult F. scutaria seed the reef with Symbiodinium during spawning and the exuded Symbiodinium release trehalose into the environment, which acts as a chemoattractant for F. scutaria larvae and as an initiator of feeding behavior- the first stages toward establishing the coral-Symbiodinium relationship. Because trehalose is a fixed carbon compound, this cue would accurately demonstrate to the cnidarian larvae the photosynthetic ability of the potential symbiont in the ambient environment. To our knowledge, this is the first report of a chemical cue attracting the motile coral larvae to the symbiont
The effects of environmental enrichment on nicotine sensitization in a rodent model of schizophrenia
Environmental enrichment, for more than fifty years, has shown to increase learning in behaviors and to alter some brain structures (Renner and Rosenzweig). Some brain changes that occur when environmental enrichment is implemented include the following: increases in cortical thickness, especially the occipital cortex, increases in size of neuronal cell bodies, number of dendrites and dendritic spines, increases in astrocyte branching, increases in the number of brain blood capillaries, and increases in mitochondria (an indication of higher metabolic activity) (Stairs and Bard). It has been shown in research studies that rats in the environmental enrichment group are less sensitive to nicotine effects, both repeated and acute, than rats in isolated situations (Green et al). This is so because enrichment changes the intensity of the acute administration of drugs of abuse. Rats are stimulated by the environment, rather than a particular stimulant
The risk, burden, and management of non-communicable diseases in cerebral palsy: a scoping review.
AIM: To examine the risk, burden, and management of non-communicable diseases (NCDs) among people with cerebral palsy (CP). METHOD: Databases (Ovid MEDLINE, Embase Ovid, CINAHL Plus) were systematically searched up to August 2017. Data on the prevalence of risk factors for, and the burden and management of, cardiovascular diseases, diabetes, cancers, and respiratory diseases were extracted. RESULTS: Thirty-six studies that examined the prevalence of risk factors among people with CP were identified. There was inconsistent evidence that people with CP had higher prevalence of metabolic risk factors such as hypertension, hyperlipidaemia, and obesity, but strong evidence that they participated in low levels of physical activity, compared with people without CP. Seven studies reported on the burden of NCDs. Adults with CP had a higher risk of NCDs, including stroke, chronic obstructive pulmonary disease, and other heart conditions, and death due to NCDs, including cancers, chronic obstructive pulmonary disease, stroke, and ischaemic heart disease, compared with the general population. Only one study reported on the management of NCD, specifically the uptake of breast cancer screening among females. INTERPRETATION: The burden of NCDs is higher among adults with CP compared with the general population. Further research is required to determine the prevalence of metabolic risk factors and management of NCDs among people with CP. WHAT THIS PAPER ADDS: Adults with cerebral palsy (CP) have an increased risk of non-communicable diseases (NCDs) and increased risk of death because of NCDs. Evidence is inconsistent about the elevated prevalence of metabolic risk factors for NCDs. Evidence is consistent that people with CP participate in reduced physical activity. Only one study reported on management of NCD among people with CP. Available evidence suggests people with CP are less likely to receive preventive medicine
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