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Behavioral recovery and spinal motoneuron remodeling after polyethylene glycol fusion repair of singly cut and ablated sciatic nerves
No full textPolyethylene glycol repair (PEG-fusion) of severed sciatic axons restores their axoplasmic and membrane continuity, prevents Wallerian degeneration, maintains muscle fiber innervation, and greatly improves recovery of voluntary behaviors. We examined alterations in spinal connectivity and motoneuron dendritic morphology as one potential mechanism for improved behavioral function after PEG-fusion. At 2–112 days after a single-cut or allograft PEG-fusion repair of transected or ablated sciatic nerves, the number, size, location, and morphology of motoneurons projecting to the tibialis anterior muscle were assessed by retrograde labeling. For both lesion types, labeled motoneurons were found in the appropriate original spinal segment, but also in inappropriate segments, indicating mis-pairings of proximal-distal segments of PEG-fused motor axons. Although the number and somal size of motoneurons was unaffected, dendritic distributions were altered, indicating that PEG-fusion preserves spinal motoneurons but reorganizes their connectivity. This spinal reorganization may contribute to the remarkable behavioral recovery seen after PEG-fusion repair
Photonuclear production, chemistry, and in vitro evaluation of the theranostic radionuclide Sc
No full textBackground: In molecular imaging and nuclear medicine, theranostic agents that integrate radionuclide pairs are successfully being used for individualized care, which has led to rapidly growing interest in their continued development. These compounds, which are radiolabeled with one radionuclide for imaging and a chemically identical or similar radionuclide for therapy, may improve patient-specific treatment and outcomes by matching the properties of different radionuclides with a targeting vector for a particular tumor type. One proposed theranostic radionuclide is scandium-47 (Sc, T = 3.35 days), which can be used for targeted radiotherapy and may be paired with the positron emitting radionuclides, Sc (T = 3.89 h) and 44Sc (T = 3.97 h) for imaging. The aim of this study was to investigate the photonuclear production of Sc via the Ti(γ,p)Sc reaction using an electron linear accelerator (eLINAC), separation and purification of Sc, the radiolabeling of somatostatin receptor-targeting peptide DOTATOC with Sc, and in vitro receptor-mediated binding of [Sc]Sc-DOTATOC in AR42J somatostatin receptor subtype two (SSTR2) expressing rat pancreatic tumor cells. Results: The rate of Sc production in a stack of natural titanium foils (n = 39) was 8 × 10 Bq/mA·h (n = 3). Irradiated target foils were dissolved in 2.0 M HSO under reflux. After dissolution, trivalent Sc ions were separated from natural Ti using AG MP-50 cation exchange resin. The recovered 47Sc was then purified using CHELEX 100 ion exchange resin. The average decay-corrected two-step Sc recovery (n = 9) was (77 ± 7)%. A radiolabeling yield of > 99.9% of [Sc]Sc-DOTATOC (0.384 mg in 0.3 mL) was achieved using 1.7 MBq of Sc. Blocking studies using Octreotide illustrated receptor-mediated uptake of [Sc]Sc-DOTATOC in AR42J cells. Conclusions: Sc can be produced via the Ti(γ,p)Sc reaction and separated from natural Ti targets with a yield and radiochemical purity suitable for radiolabeling of peptides for in vitro studies. The data in this work supports the potential use of eLINACs for studies of photonuclear production of medical radionuclides and the future development of high-intensity eLINAC facilities capable of producing relevant quantities of carrier-free radionuclides currently inaccessible via routine production pathways or limited due to costly enriched targets
Does the healthcare educational market respond to short-run local demand?
No full textThe Patient Protection and Affordable Care Act (ACA) increased demand for healthcare across the U.S., but it is unclear if or how the supply side has responded to meet this demand. In this paper, we take advantage of plausibly exogenous geographical heterogeneity in the ACA to examine the healthcare education sector's response to increased demand for healthcare services. We look across educational fields, types of degrees, and types of institutions, paying particular attention to settings where our conceptual model predicts heightened responses. We find no statistically significant evidence of increases in graduates and can rule out fairly modest effects. This implies that healthcare production may have adjusted to increased demand from insurance expansion in other ways rather than primarily through new graduates of local healthcare educational markets
Childhood poverty and the organization of structural brain connectome
No full textSocioeconomic disadvantage is associated with atypical development in specific brain regions, yet the relation between poverty and whole brain network organization (i.e., the connectome, a set of brain regions connected with neuronal pathways) has not been characterized. Developmental studies indicate that the connectome undergoes rapid change during childhood and is consequently likely to be highly sensitive to both salutary and detrimental influences. We investigated associations between the socioeconomic disparities measured by the income-to-needs ratio (INR) in childhood and structural brain network organization with 144 healthy children between 6 and 11 years of age (mean age = 8 years). INR of girls was positively and logarithmically associated with the extent to which brain networks were efficiently organized, suggesting that girls in more impoverished environments had less efficient brain network organization. Lower INR was associated with network inefficiency in multiple cortical regions including prefrontal cortex, cingulate, and insula, and in subcortical regions including the hippocampus and amygdala. These findings suggest that childhood poverty may result in wide-spread disruptions of the brain connectome among girls, particularly at the lowest INR levels, and are differentially expressed in females and males
Pd Nanoparticles Stabilized by Hypercrosslinked Polystyrene Catalyze Selective Triple C-C Bond Hydrogenation and Suzuki Cross-Coupling
No full textThis paper describes the synthesis of Pd-containing catalysts based on nonfunctionalized hypercrosslinked polystyrene via impregnation with Pd acetate. Developed Pd nanoparticulate catalyst allowed achieving conversion of aryl halide up to 90% in Suzuki cross-coupling reaction under mild conditions and at the absence of phase-transfer agents. During the selective hydrogenation of triple C-C bond of 2-methyl-3-butyn-2-ol, up to 96% selectivity with respect to corresponding olefinic alcohol was found at 95% conversion. The influences of the procedure of catalyst synthesis like precursor decomposition and reductive activation method on Pd nanoparticle formation are discussed
Drosophila macrophages switch to aerobic glycolysis to mount effective antibacterial defense
No full textMacrophage-mediated phagocytosis and cytokine production represent the front lines of resistance to bacterial invaders. A key feature of this pro-inflammatory response in mammals is the complex remodeling of cellular metabolism towards aerobic glycolysis. Although the function of bactericidal macrophages is highly conserved, the metabolic remodeling of insect macrophages remains poorly understood. Here, we used adults of the fruit fly Drosophila melanogaster to investigate the metabolic changes that occur in macrophages during the acute and resolution phases of Streptococcus-induced sepsis. Our studies revealed that orthologs of Hypoxia inducible factor 1α (HIF1α) and Lactate dehydrogenase (LDH) are required for macrophage activation, their bactericidal function, and resistance to infection, thus documenting the conservation of this cellular response between insects and mammals. Further, we show that macrophages employing aerobic glycolysis induce changes in systemic metabolism that are necessary to meet the biosynthetic and energetic demands of their function and resistance to bacterial infection
Efficacy of a high school extensive reading intervention for English learners with reading difficulties.
No full textThis study examined the effects of Reading Intervention for Adolescents, a 2-year extensive reading intervention targeting current and former English learners identified as struggling readers based on their performance on the state accountability assessment. Students who enrolled at three participating urban high schools were randomly assigned to the Reading Intervention for Adolescents treatment condition ( = 175) or a business-as-usual comparison condition. Students assigned to the treatment condition participated in the intervention for approximately 50 min daily for 2 school years in lieu of a school-provided elective course, which business-as-usual students took consistent with typical scheduling. Findings revealed significant effects for the treatment condition on sentence-level fluency and comprehension ( = 0.18) and on a proximal measure of vocabulary learning ( = .41), but not on standardized measures of word reading, vocabulary, or reading comprehension ( range: −0.09 to 0.06). Post hoc moderation analyses investigated whether initial proficiency levels interacted with treatment effects. On sentence-level fluency and comprehension and on vocabulary learning, initial scores were significantly associated with treatment effects—however, in opposite directions. Students who scored low at baseline on sentence reading and comprehension scored relatively higher at posttest on that measure, whereas students who scored high at baseline on the proximal vocabulary measure scored relatively higher at posttest on that measure. The discussion focuses on the difficulty of remediating persistent reading difficulties in high school, particularly among English learners, who are often still in the process of acquiring academic proficiency in English
Does the built environment influence the effectiveness of behavioral weight management interventions?
No full textOutcomes of behavioral lifestyle interventions for promoting weight loss vary widely across participants. The effectiveness of a weight management intervention may depend on a person's environmental context. This study compared short- and longer-term effects of a structured nationwide weight management program for people living in neighborhoods with different levels of walkability and different access to recreational places (parks, fitness facilities). Drawing on the health production model, we tested competing hypotheses for whether treatment effects of the program complement environmental supports or substitute for environmental constraints. We studied the US Department of Veterans Affairs (VA) MOVE! weight management program using VA electronic heath record data (2009–2014) and a difference-in-differences design with an inverse propensity score matched comparison group. A total of 114,256 program participants and 498,494 non-participants comprised the sample. Built environment features were measured within one-mile of each person's home. We estimated program effects on body mass index (BMI) for subgroups with different built environments at 6-, 12-, 18-, and 24-month follow-up using linear regressions with person and year fixed effects. At 6 months, the program reduced BMI by 0.4–0.6 kg/m among men and 0.3–0.5 kg/m among women. The effect diminished at 12, 18, and 24 months. The program effect did not vary significantly across subgroups with different walkability, park access, or fitness facility access. The MOVE! program was not sensitive to environmental context. Results did not lend support to either hypothesis that the MOVE! program complements or substitutes for a person's built environment to affect weight management outcomes
Collision-energy dependence of correlations in Au + Au collisions at energies available at the BNL Relativistic Heavy Ion Collider
No full textWe present two-particle correlations as a function of event centrality for Au+Au collisions at = 7.7, 11.5, 14.5, 19.6, 27, 39, 62.4, and 200 GeV at the Relativistic Heavy Ion Collider using the STAR detector. These results are compared to previous measurements from CERES at the Super Proton Synchrotron and from ALICE at the Large Hadron Collider. The data are compared with UrQMD model calculations and with a model based on a Boltzmann-Langevin approach incorporating effects from thermalization. The relative dynamical correlations for Au+Au collisions at = 200 GeV show a power-law dependence on the number of participant nucleons and agree with the results for Pb+Pb collisions at = 2.76 TeV from ALICE. As the collision energy is lowered from = 200 to 7.7 GeV, the centrality dependence of the relative dynamical correlations departs from the power-law behavior observed at the higher collision energies. In central collisions, the relative dynamical correlations increase with collision energy up to = 200 GeV in contrast to previous measurements that showed little dependence on the collision energy
Tying enforcement to prices in emissions markets: An experimental evaluation
No full textWe present results from laboratory emissions permit markets designed to investigate the transmission of abatement cost risk to firms' compliance behavior and regulatory enforcement strategies. With a fixed expected marginal penalty, abatement cost shocks produced significant violations and emissions volatility as predicted. Tying the monitoring probability to average permit prices effectively eliminated noncompliance, but transmitted abatement cost risk to monitoring effort. Tying the penalty to average prices reduced violations, but did not eliminate them. Some individuals in these treatments sold permits at low prices, presumably in an attempt to weaken enforcement. While tying sanctions directly to prevailing permit prices has theoretical and practical advantages over tying monitoring to prices, our results suggest that tying sanctions to prices may not be as effective as predicted without additional modifications