5,181 research outputs found

    Preparing to Teach: Redeeming the Potentialities of the Present Through Conversations of Practice

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    A prospective teacher and a teacher educator enter into a yearlong conversation seeking greater curricular physicality and materiality within its enactment. Dewey\u27s (1938) temporal educative relation of teaching and learning as an ever-present process is helpful, asking both parties to dwell mindfully at the intersections of teaching/learning situations and interactions. Attention turns to the lived curricular features and consequences of preparing teachers to teach as an ever-present process. The role and place of self-other negotiation is illuminated within curricular enactment, giving expression to teaching/learning as an ever-present process. Pedagogical significances are redeemed through greater teaching mindfulness of the temporality at play within the present

    Associations between social risk factors and surgical site infections after colectomy and abdominal hysterectomy

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    Importance: Surgical site infection (SSI) is an important patient safety outcome. Although social risk factors have been linked to many adverse health outcomes, it is unknown whether such factors are associated with higher rates of SSI. Objectives: To determine whether social risk factors, including race/ethnicity, insurance status, and neighborhood income, are associated with higher rates of SSI after colectomy or abdominal hysterectomy, 2 surgical procedures for which SSI rates are publicly reported and included in pay-for-performance programs by Medicare and other groups. Design, Setting, and Participants: This cross-sectional study analyzed adults undergoing colectomy or abdominal hysterectomy, as captured in State Inpatient Databases for Arizona, Florida, Iowa, Massachusetts, Maryland, New York, and Vermont. Operations were performed in 2013 through 2014 at general acute care hospitals in the United States. Data analysis was conducted from October 2018 through June 2019. Exposures: Colectomy or hysterectomy. Main Outcomes and Measures: Postoperative complex SSI rates. Results: A total of 149 741 patients met the inclusion criteria, including 90 210 patients undergoing colectomies (mean [SD] age, 63.4 [15.6] years; 49 029 [54%] female; 74% white, 11% black, 9% Hispanic, and 5% other or unknown race/ethnicity) and 59 531 patients undergoing abdominal hysterectomies (mean [SD] age, 49.8 [11.8] years; 100% female; 52% white, 26% black, 14% Hispanic, and 8% other or unknown race/ethnicity). In the colectomy cohort, 34% had private insurance, 52% had Medicare, 9% had Medicaid, and 5% had other or unknown insurance or were uninsured; 24% were from the lowest quartile of median zip code income. In the hysterectomy cohort, 57% had private insurance, 16% had Medicare, 19% had Medicaid, and 3% had other or unknown insurance or were uninsured; 27% were from the lowest-income zip codes. Within 30 days of surgery, SSI rates were 2.55% for the colectomy cohort and 0.61% for the hysterectomy cohort. For colectomy, black race (adjusted odds ratio [AOR], 0.71; 95% CI, 0.61-0.82) was associated with lower odds of SSI, whereas Medicare (AOR, 1.25; 95% CI, 1.10-1.41), Medicaid (AOR, 1.23; 95% CI, 1.06-1.44), and low neighborhood income (AOR, 1.14; 95% CI, 1.01-1.29) were associated with higher odds of SSI. For hysterectomy, no social risk factors that were examined in this study had statistically significant associations with SSI after adjustment for clinical risk. Conclusions and Relevance: Inconsistent associations between social risk factors and SSIs were found. For colectomy, infection prevention programs targeting low-income groups may be important for reducing disparities in this postoperative outcome, and policy makers could consider taking social risk factors into account when evaluating hospital performance

    Distinct Aspects of the Early Environment Contribute to Associative Memory, Cued Attention, and Memory-Guided Attention: Implications for Academic Achievement

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    Childhood socioeconomic status (SES) is associated with numerous aspects of cognitive development and disparities in academic achievement. The specific environmental factors that contribute to these disparities remain poorly understood. We used observational methods to characterize three aspects of the early environment that may contribute to SES-related differences in cognitive development: violence exposure, cognitive stimulation, and quality of the physical environment. We evaluated the associations of these environmental characteristics with associative memory, cued attention, and memory-guided attention in a sample of 101 children aged 60–75 months. We further investigated whether these specific cognitive abilities mediated the association between SES and academic achievement 18 months later. Violence exposure was specifically associated with poor associative memory, but not cued attention or memory-guided attention. Cognitive stimulation and higher quality physical environment were positively associated with cued attention accuracy, but not after adjusting for all other environmental variables. The quality of the physical environment was associated with memory-guided attention accuracy. Of the cognitive abilities examined, only memory-guided attention contributed to SES-related differences in academic achievement. These findings suggest specificity in how particular aspects of early environmental experience scaffold different types of attention and memory subserved by distinct neural circuits and shed light on a novel cognitive-developmental mechanism underlying SES-related disparities in academic achievement

    Automated Radiosynthesis of cis- and trans-4-[18F]Fluoro-L-proline using [18F]Fluoride

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    The positron emission tomography imaging agents cis- and trans-4-[18F]fluoro-l-proline are used for the detection of numerous diseases such as pulmonary fibrosis and various carcinomas. These imaging agents are typically prepared by nucleophilic fluorination of 4-hydroxy-l-proline derivatives, with [18F]fluoride, followed by deprotection. Although effective radiofluorination reactions have been developed, the overall radiosynthesis process is suboptimal due to deprotection methods that are performed manually, require multiple steps, or involve harsh conditions. Here we describe the development of two synthetic routes that allow access to precursors, which undergo highly selective radiofluorination reactions and rapid deprotection, under mild acidic conditions. These methods were found to be compatible with automation, avoiding manual handling of radioactive intermediates

    When good news leads to bad choices

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    Pigeons and other animals sometimes deviate from optimal choice behavior when given informative signals for delayed outcomes. For example, when pigeons are given a choice between an alternative that always leads to food after a delay and an alternative that leads to food only half of the time after a delay, preference changes dramatically depending on whether the stimuli during the delays are correlated with (signal) the outcomes or not. With signaled outcomes, pigeons show a much greater preference for the suboptimal alternative than with unsignaled outcomes. Key variables and research findings related to this phenomenon are reviewed, including the effects of durations of the choice and delay periods, probability of reinforcement, and gaps in the signal. We interpret the available evidence as reflecting a preference induced by signals for good news in a context of uncertainty. Other explanations are briefly summarized and compared

    Obesity and the food environment: income and ethnicity differences among people with diabetes: the Diabetes Study of Northern California (DISTANCE).

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    ObjectiveIt is unknown whether any association between neighborhood food environment and obesity varies according to individual income and/or race/ethnicity. The objectives of this study were to test whether there was an association between food environments and obesity among adults with diabetes and whether this relationship differed according to individual income or race/ethnicity.Research design and methodsSubjects (n = 16,057) were participants in the Diabetes Study of Northern California survey. Kernel density estimation was used to create a food environment score for each individual's residence address that reflected the mix of healthful and unhealthful food vendors nearby. Logistic regression models estimated the association between the modeled food environment and obesity, controlling for confounders, and testing for interactions between food environment and race/ethnicity and income.ResultsThe authors found that more healthful food environments were associated with lower obesity in the highest income groups (incomes 301-600% and >600% of U.S. poverty line) among whites, Latinos, and Asians. The association was negative, but smaller and not statistically significant, among high-income blacks. On the contrary, a more healthful food environment was associated with higher obesity among participants in the lowest-income group (<100% poverty threshold), which was statistically significant for black participants in this income category.ConclusionsThese findings suggest that the availability of healthful food environments may have different health implications when financial resources are severely constrained

    Socioeconomic Disparities in Academic Achievement: A Multi-Modal Investigation of Neural Mechanisms in Children and Adolescents

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    Growing evidence suggests that childhood socioeconomic status (SES) influences neural development, which may contribute to the well-documented SES-related disparities in academic achievement. However, the particular aspects of SES that impact neural structure and function are not well understood. Here, we investigate associations of childhood SES and a potential mechanism—degree of cognitive stimulation in the home environment—with cortical structure, white matter microstructure, and neural function during a working memory (WM) task across development. Analyses included 53 youths (age 6–19 years). Higher SES as reflected in the income-to-needs ratio was associated with higher parent-reported achievement, WM performance, and cognitive stimulation in the home environment. Although SES was not significantly associated with cortical thickness, children raised in more cognitively stimulating environments had thicker cortex in the frontoparietal network and cognitive stimulation mediated the assocation between SES and cortical thickness in the frontoparietal network. Higher family SES was associated with white matter microstructure and neural activation in the frontoparietal network during a WM task, including greater fractional anisotropy (FA) in the right and left superior longitudinal fasciculi (SLF), and greater BOLD activation in multiple regions of the prefrontal cortex during WM encoding and maintenance. Greater FA and activation in these regions was associated higher parent-reported achievement. Together, cognitive stimulation, WM performance, FA in the SLF, and prefrontal activation during WM encoding and maintenance significantly mediated the association between SES and parent-reported achievement. These findings highlight potential neural, cognitive, and environmental mechanisms linking SES with academic achievement and suggest that enhancing cognitive stimulation in the home environment might be one effective strategy for reducing SES-related disparities in academic outcomes

    Manipulating adenovirus hexon hypervariable loops dictates immune neutralisation and coagulation factor X-dependent cell interaction in vitro and in vivo

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    Adenoviruses are common pathogens, mostly targeting ocular, gastrointestinal and respiratory cells, but in some cases infection disseminates, presenting in severe clinical outcomes. Upon dissemination and contact with blood, coagulation factor X (FX) interacts directly with the adenovirus type 5 (Ad5) hexon. FX can act as a bridge to bind heparan sulphate proteoglycans, leading to substantial Ad5 hepatocyte uptake. FX “coating” also protects the virus from host IgM and complement-mediated neutralisation. However, the contribution of FX in determining Ad liver transduction whilst simultaneously shielding the virus from immune attack remains unclear. In this study, we demonstrate that the FX protection mechanism is not conserved amongst Ad types, and identify the hexon hypervariable regions (HVR) of Ad5 as the capsid proteins targeted by this host defense pathway. Using genetic and pharmacological approaches, we manipulate Ad5 HVR interactions to interrogate the interplay between viral cell transduction and immune neutralisation. We show that FX and inhibitory serum components can co-compete and virus neutralisation is influenced by both the location and extent of modifications to the Ad5 HVRs. We engineered Ad5-derived HVRs into the rare, native non FX-binding Ad26 to create Ad26.HVR5C. This enabled the virus to interact with FX at high affinity, as quantified by surface plasmon resonance, FX-mediated cell binding and transduction assays. Concomitantly, Ad26.HVR5C was also sensitised to immune attack in the absence of FX, a direct consequence of the engineered HVRs from Ad5. In both immune competent and deficient animals, Ad26.HVR5C hepatic gene transfer was mediated by FX following intravenous delivery. This study gives mechanistic insight into the pivotal role of the Ad5 HVRs in conferring sensitivity to virus neutralisation by IgM and classical complement-mediated attack. Furthermore, through this gain-of-function approach we demonstrate the dual functionality of FX in protecting Ad26.HVR5C against innate immune factors whilst determining liver targeting

    Assembly and function of AP-3 complexes in cells expressing mutant subunits

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    The mouse mutants mocha and pearl are deficient in the AP-3 δ and β3A subunits, respectively. We have used cells from these mice to investigate both the assembly of AP-3 complexes and AP-3 function. In mocha cells, the β3 and μ3 subunits coassemble into a heterodimer, whereas the σ3 subunit remains monomeric. In pearl cells, the δ and σ3 subunits coassemble into a heterodimer, whereas μ3 gets destroyed. The yeast two hybrid system was used to confirm these interactions, and also to demonstrate that the A (ubiquitous) and B (neuronal-specific) isoforms of β3 and μ3 can interact with each other. Pearl cell lines were generated that express β3A, β3B, a β3Aβ2 chimera, two β3A deletion mutants, and a β3A point mutant lacking a functional clathrin binding site. All six constructs assembled into complexes and were recruited onto membranes. However, only β3A, β3B, and the point mutant gave full functional rescue, as assayed by LAMP-1 sorting. The β3Aβ2 chimera and the β3A short deletion mutant gave partial functional rescue, whereas the β3A truncation mutant gave no functional rescue. These results indicate that the hinge and/or ear domains of β3 are important for function, but the clathrin binding site is not needed

    The Effect of Oral Leucine on Protein Metabolism in Adolescents with Type 1 Diabetes Mellitus

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    Lack of insulin results in a catabolic state in subjects with insulin-dependent diabetes mellitus which is reversed by insulin treatment. Amino acid supply, especially branched chain amino acids such as leucine, enhances protein synthesis in both animal and human studies. This small study was undertaken to assess the acute effect of supplemental leucine on protein metabolism in adolescents with type 1 diabetes. L-[1-13C] Leucine was used to assess whole-body protein metabolism in six adolescent females (16–18 yrs) with type 1 diabetes during consumption of a basal diet (containing 58 μmoles leucine/kg/h) and the basal diet with supplemental leucine (232 μmoles leucine/kg/h). Net leucine balance was significantly higher with supplemental leucine (56.33 ± 12.13 μmoles leucine/kg body weight/hr) than with the basal diet (−11.7 ± −5.91, P < .001) due to reduced protein degradation (49.54 ± 18.80 μmoles leucine/kg body weight/hr) compared to the basal diet (109 ± 13.05, P < .001)
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