120 research outputs found
Correlation of umbilical cord blood haematopoietic stem and progenitor cell levels with birth weight: implications for a prenatal influence on cancer risk
We examined the relation with birth weight and umbilical cord blood concentrations of haematopoietic stem and progenitor populations in 288 singleton infants. Across the whole range of birth weight, there was a positive relation between birth weight and CD34+CD38β cells, with each 500βg increase in birth weight being associated with a 15.5% higher (95% confidence interval: 1.6β31.3%) cell concentration. CD34+ and CD34+c-kit+ cells had J-shaped relations and CFU-GM cells had a U-shaped relation with birth weight. Among newborns with β©Ύ3000βg birth weights, concentrations of these cells increased with birth weight, while those below 3000βg had higher stem cell concentrations than the reference category of 3000β3499βg. Adjustment for cord blood plasma insulin-like growth factor-1 levels weakened the stem and progenitor cellβbirth weight associations. The positive associations between birth weight and stem cell measurements for term newborns with a normal-to-high birth weight support the stem cell burden hypothesis of cancer risk
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Identifying predictors of translocation success in rare plant species
The fundamental goal of a rare plant translocation is to create self-sustaining populations with the evolutionary resilience to persist in the long term. Yet, most plant translocation syntheses focus on a few factors influencing short-term benchmarks of success (e.g., survival and reproduction). Short-term benchmarks can be misleading when trying to infer future growth and viability because the factors that promote establishment may differ from those required for long-term persistence. We assembled a large (n = 275) and broadly representative data set of well-documented and monitored (7.9 years on average) at-risk plant translocations to identify the most important site attributes, management techniques, and species' traits for six life-cycle benchmarks and population metrics of translocation success. We used the random forest algorithm to quantify the relative importance of 29 predictor variables for each metric of success. Drivers of translocation outcomes varied across time frames and success metrics. Management techniques had the greatest relative influence on the attainment of life-cycle benchmarks and short-term population trends, whereas site attributes and species' traits were more important for population persistence and long-term trends. Specifically, large founder sizes increased the potential for reproduction and recruitment into the next generation, whereas declining habitat quality and the outplanting of species with low seed production led to increased extinction risks and a reduction in potential reproductive output in the long-term, respectively. We also detected novel interactions between some of the most important drivers, such as an increased probability of next-generation recruitment in species with greater seed production rates, but only when coupled with large founder sizes. Because most significant barriers to plant translocation success can be overcome by improving techniques or resolving site-level issues through early intervention and management, we suggest that by combining long-term monitoring with adaptive management, translocation programs can enhance the prospects of achieving long-term success
Who Needs Microtubules? Myogenic Reorganization of MTOC, Golgi Complex and ER Exit Sites Persists Despite Lack of Normal Microtubule Tracks
A wave of structural reorganization involving centrosomes, microtubules, Golgi complex and ER exit sites takes place early during skeletal muscle differentiation and completely remodels the secretory pathway. The mechanism of these changes and their functional implications are still poorly understood, in large part because all changes occur seemingly simultaneously. In an effort to uncouple the reorganizations, we have used taxol, nocodazole, and the specific GSK3-Ξ² inhibitor DW12, to disrupt the dynamic microtubule network of differentiating cultures of the mouse skeletal muscle cell line C2. Despite strong effects on microtubules, cell shape and cell fusion, none of the treatments prevented early differentiation. Redistribution of centrosomal proteins, conditional on differentiation, was in fact increased by taxol and nocodazole and normal in DW12. Redistributions of Golgi complex and ER exit sites were incomplete but remained tightly linked under all circumstances, and conditional on centrosomal reorganization. We were therefore able to uncouple microtubule reorganization from the other events and to determine that centrosomal proteins lead the reorganization hierarchy. In addition, we have gained new insight into structural and functional aspects of the reorganization of microtubule nucleation during myogenesis
Adolescent Brain Development and the Risk for Alcohol and Other Drug Problems
Dynamic changes in neurochemistry, fiber architecture, and tissue composition occur in the adolescent brain. The course of these maturational processes is being charted with greater specificity, owing to advances in neuroimaging and indicate grey matter volume reductions and protracted development of white matter in regions known to support complex cognition and behavior. Though fronto-subcortical circuitry development is notable during adolescence, asynchronous maturation of prefrontal and limbic systems may render youth more vulnerable to risky behaviors such as substance use. Indeed, binge-pattern alcohol consumption and comorbid marijuana use are common among adolescents, and are associated with neural consequences. This review summarizes the unique characteristics of adolescent brain development, particularly aspects that predispose individuals to reward seeking and risky choices during this phase of life, and discusses the influence of substance use on neuromaturation. Together, findings in this arena underscore the importance of refined research and programming efforts in adolescent health and interventional needs
Thoracic epidural analgesia inhibits the neuro-hormonal but not the acute inflammatory stress response after radical retropubic prostatectomy
<p>Background. Epidural anaesthesia and analgesia has been shown to suppress the neurohormonal stress response, but its role in the inflammatory response is unclear. The primary aim was to assess whether the choice of analgesic technique influences these processes in patients undergoing radical retropubic prostatectomy.</p><p>Methods. Twenty-six patients were randomized to Group P (systemic opioid-based analgesia) or Group E (thoracic epidural-based analgesia) perioperatively. Induction and maintenance of anaesthesia followed a standardized protocol. The following measurements were made perioperatively: plasma cortisol, glucose, insulin, C-reactive proteins, leucocyte count, plasma cytokines [interleukin (IL)-6, tumour necrosis factor (TNF)-alpha], and pokeweed mitogen-stimulated cytokines [interferon (IFN)-gamma, IL-2, IL-12p70, IL-10, IL-4, and IL-17]. Other parameters recorded were pain, morphine consumption, and perioperative complications.</p><p>Results. Plasma concentration of cortisol and glucose were significantly higher in Group P compared with Group E at the end of surgery, the mean difference was 232 nmol litre(-1) [95% confidence interval (CI) 84-381] (P=0.004) and 1.6 mmol litre(-1) (95% CI 0.6-2.5) (P=0.003), respectively. No significant differences were seen in IL-6 and TNF-alpha at 24 h (P=0.953 and 0.368, respectively) and at 72 h (P=0.931 and 0.691, respectively). IL-17 was higher in Group P compared with Group E, both at 24 h (P=0.001) and 72 h (P=0.018) after operation. Pain intensity was significantly greater in Group P compared with Group E (P</p><p>Conclusions. In this small prospective randomized study, thoracic epidural analgesia reduced the early postoperative stress response but not the acute inflammatory response after radical retrobupic prostatectomy, suggesting that other pathways are involved during the acute phase reaction.</p>
Status of catalytic combustion R & D for the department of energy advanced turbine systems program
This paper discusses some of the advanced concepts and research and development associated with implementing catalytic combustion to achieve ultra-low-NO<SUB>x</SUB> emissions in the next generation of land-based gas turbine engines. In particular, the paper presents current development status and design challenges being addressed by Siemens Westinghouse Power Corp. for large industrial engines (>200 MW) and by Solar Turbines for smaller engines (<20 MW) as part of the U.S. Department of Energy's (DOE) Advanced Turbine Systems (ATS) program. Operational issues in implementing catalytic combustion and the current needs for research in catalyst durability and operability are also discussed. This paper indicates how recent advances in reactor design and catalytic coatings have made catalytic combustion a viable technology for advanced turbine engines and how further research and development may improve catalytic combustion systems to better meet the durability and operability challenges presented by the high-efficiency, ultra-low emissions ATS program goals
Applying the integral equations method to the problem of synthesizing vowels of the Russian language
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