24 research outputs found

    Plasma REST: a novel candidate biomarker of Alzheimer's disease is modified by psychological intervention in an at-risk population.

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    The repressor element 1-silencing transcription (REST) factor is a key regulator of the aging brain's stress response. It is reduced in conditions of stress and Alzheimer's disease (AD), which suggests that increasing REST may be neuroprotective. REST can be measured peripherally in blood plasma. Our study aimed to (1) examine plasma REST levels in relation to clinical and biological markers of neurodegeneration and (2) alter plasma REST levels through a stress-reduction intervention-mindfulness training. In study 1, REST levels were compared across the following four well-characterized groups: healthy elderly (n=65), mild cognitive impairment who remained stable (stable MCI, n=36), MCI who later converted to dementia (converter MCI, n=29) and AD (n=65) from the AddNeuroMed cohort. REST levels declined with increasing severity of risk and impairment (healthy elderly>stable MCI>converter MCI>AD, F=6.35, P<0.001). REST levels were also positively associated with magnetic resonance imaging-based hippocampal and entorhinal atrophy and other putative blood-based biomarkers of AD (Ps<0.05). In study 2, REST was measured in 81 older adults with psychiatric risk factors for AD before and after a mindfulness-based stress reduction intervention or an education-based placebo intervention. Mindfulness-based training caused an increase in REST compared with the placebo intervention (F=8.57, P=0.006), and increased REST was associated with a reduction in psychiatric symptoms associated with stress and AD risk (Ps<0.02). Our data confirm plasma REST associations with clinical severity and neurodegeneration, and originally, that REST is modifiable by a psychological intervention with clinical benefit

    Plasma REST: A novel candidate biomarker of Alzheimer\u27s disease is modified by psychological intervention in an at-risk population

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    The repressor element 1-silencing transcription (REST) factor is a key regulator of the aging brain’s stress response. It is reduced in conditions of stress and Alzheimer’s disease (AD), which suggests that increasing REST may be neuroprotective. REST can be measured peripherally in blood plasma. Our study aimed to (1) examine plasma REST levels in relation to clinical and biological markers of neurodegeneration and (2) alter plasma REST levels through a stress-reduction intervention—mindfulness training. In study 1, REST levels were compared across the following four well-characterized groups: healthy elderly (n=65), mild cognitive impairment who remained stable (stable MCI, n=36), MCI who later converted to dementia (converter MCI, n=29) and AD (n=65) from the AddNeuroMed cohort. REST levels declined with increasing severity of risk and impairment (healthy elderly>stable MCI>converter MCI>AD, F=6.35, P<0.001). REST levels were also positively associated with magnetic resonance imaging-based hippocampal and entorhinal atrophy and other putative blood-based biomarkers of AD (Ps<0.05). In study 2, REST was measured in 81 older adults with psychiatric risk factors for AD before and after a mindfulness-based stress reduction intervention or an education-based placebo intervention. Mindfulness-based training caused an increase in REST compared with the placebo intervention (F=8.57, P=0.006), and increased REST was associated with a reduction in psychiatric symptoms associated with stress and AD risk (Ps<0.02). Our data confirm plasma REST associations with clinical severity and neurodegeneration, and originally, that REST is modifiable by a psychological intervention with clinical benefit

    Production of phi mesons at mid-rapidity in sqrt(s_NN) = 200 GeV Au+Au collisions at RHIC

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    We present the first results of meson production in the K^+K^- decay channel from Au+Au collisions at sqrt(s_NN) = 200 GeV as measured at mid-rapidity by the PHENIX detector at RHIC. Precision resonance centroid and width values are extracted as a function of collision centrality. No significant variation from the PDG accepted values is observed. The transverse mass spectra are fitted with a linear exponential function for which the derived inverse slope parameter is seen to be constant as a function of centrality. These data are also fitted by a hydrodynamic model with the result that the freeze-out temperature and the expansion velocity values are consistent with the values previously derived from fitting single hadron inclusive data. As a function of transverse momentum the collisions scaled peripheral.to.central yield ratio RCP for the is comparable to that of pions rather than that of protons. This result lends support to theoretical models which distinguish between baryons and mesons instead of particle mass for explaining the anomalous proton yield.Comment: 326 authors, 24 pages text, 23 figures, 6 tables, RevTeX 4. To be submitted to Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Inflammatory biomarkers in Alzheimer's disease plasma.

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    Plasma biomarkers for Alzheimer's disease (AD) diagnosis/stratification are a "Holy Grail" of AD research and intensively sought; however, there are no well-established plasma markers. A hypothesis-led plasma biomarker search was conducted in the context of international multicenter studies. The discovery phase measured 53 inflammatory proteins in elderly control (CTL; 259), mild cognitive impairment (MCI; 199), and AD (262) subjects from AddNeuroMed. Ten analytes showed significant intergroup differences. Logistic regression identified five (FB, FH, sCR1, MCP-1, eotaxin-1) that, age/APOε4 adjusted, optimally differentiated AD and CTL (AUC: 0.79), and three (sCR1, MCP-1, eotaxin-1) that optimally differentiated AD and MCI (AUC: 0.74). These models replicated in an independent cohort (EMIF; AUC 0.81 and 0.67). Two analytes (FB, FH) plus age predicted MCI progression to AD (AUC: 0.71). Plasma markers of inflammation and complement dysregulation support diagnosis and outcome prediction in AD and MCI. Further replication is needed before clinical translation

    J/psi production from proton-proton collisions at sqrt(s) = 200 GeV

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    J/psi production has been measured in proton-proton collisions at sqrt(s)= 200 GeV over a wide rapidity and transverse momentum range by the PHENIX experiment at RHIC. Distributions of the rapidity and transverse momentum, along with measurements of the mean transverse momentum and total production cross section are presented and compared to available theoretical calculations. The total J/psi cross section is 3.99 +/- 0.61(stat) +/- 0.58(sys) +/- 0.40(abs) micro barns. The mean transverse momentum is 1.80 +/- 0.23(stat) +/- 0.16(sys) GeV/c.Comment: 326 authors, 6 pages text, 4 figures, 1 table, RevTeX 4. To be submitted to PRL. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Measurement of Single Electron Event Anisotropy in Au+Au Collisions at sqrt(s_NN) = 200 GeV

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    The transverse momentum dependence of the azimuthal anisotropy parameter v_2, the second harmonic of the azimuthal distribution, for electrons at mid-rapidity (|eta| < 0.35) has been measured with the PHENIX detector in Au+Au collisions at sqrt(s_NN) = 200 GeV. The measurement was made with respect to the reaction plane defined at high rapidities (|eta| = 3.1 -- 3.9). From the result we have measured the v_2 of electrons from heavy flavor decay after subtraction of the v_2 of electrons from other sources such as photon conversions and Dalitz decay from light neutral mesons. We observe a non-zero single electron v_2 with a 90% confidence level in the intermediate p_T region.Comment: 330 authors, 11 pages text, RevTeX4, 9 figures, 1 tables. Submitted to Physical Review C. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Systematic Studies of the Centrality and sqrt(s_NN) Dependence of dE_T/deta and dN_ch/deta in Heavy Ion Collisions at Mid-rapidity

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    The PHENIX experiment at RHIC has measured transverse energy and charged particle multiplicity at mid-rapidity in Au+Au collisions at sqrt(s_NN) = 19.6, 130 and 200 GeV as a function of centrality. The presented results are compared to measurements from other RHIC experiments, and experiments at lower energies. The sqrt(s_NN) dependence of dE_T/deta and dN_ch/deta per pair of participants is consistent with logarithmic scaling for the most central events. The centrality dependence of dE_T/deta and dN_ch/deta is similar at all measured incident energies. At RHIC energies the ratio of transverse energy per charged particle was found independent of centrality and growing slowly with sqrt(s_NN). A survey of comparisons between the data and available theoretical models is also presented.Comment: 327 authors, 25 pages text, 19 figures, 17 tables, RevTeX 4. To be submitted to Physical Review C as a regular article. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Centrality Dependence of Charm Production from Single Electrons in Au+Au Collisions at sqrt(s_NN) = 200 GeV

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    The PHENIX experiment has measured mid-rapidity transverse momentum spectra (0.4 < p_T < 4.0 GeV/c) of single electrons as a function of centrality in Au+Au collisions at sqrt(s_NN) = 200 GeV. Contributions to the raw spectra from photon conversions and Dalitz decays of light neutral mesons are measured by introducing a thin (1.7% X_0) converter into the PHENIX acceptance and are statistically removed. The subtracted ``non-photonic'' electron spectra are primarily due to the semi-leptonic decays of hadrons containing heavy quarks (charm and bottom). For all centralities, charm production is found to scale with the nuclear overlap function, T_AA. For minimum-bias collisions the charm cross section per binary collision is N_cc^bar/T_AA = 622 +/- 57 (stat.) +/- 160 (sys.) microbarns.Comment: 326 authors, 4 pages text, 3 figures, 1 table, RevTeX 4. To be submitted to Physical Review Letters. Plain text data tables for the points plotted in figures for this and previous PHENIX publications are (or will be) publicly available at http://www.phenix.bnl.gov/papers.htm

    Inflammatory biomarkers in Alzheimer's disease plasma

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    Introduction: Plasma biomarkers for Alzheimer's disease (AD)diagnosis/stratification are a “Holy Grail” of AD research and intensively sought; however, there are no well-established plasma markers. Methods: A hypothesis-led plasma biomarker search was conducted in the context of international multicenter studies. The discovery phase measured 53 inflammatory proteins in elderly control (CTL; 259), mild cognitive impairment (MCI; 199), and AD (262)subjects from AddNeuroMed. Results: Ten analytes showed significant intergroup differences. Logistic regression identified five (FB, FH, sCR1, MCP-1, eotaxin-1)that, age/APOε4 adjusted, optimally differentiated AD and CTL (AUC: 0.79), and three (sCR1, MCP-1, eotaxin-1)that optimally differentiated AD and MCI (AUC: 0.74). These models replicated in an independent cohort (EMIF; AUC 0.81 and 0.67). Two analytes (FB, FH)plus age predicted MCI progression to AD (AUC: 0.71). Discussion: Plasma markers of inflammation and complement dysregulation support diagnosis and outcome prediction in AD and MCI. Further replication is needed before clinical translation

    International Society of Sports Nutrition Position Stand: Nutritional recommendations for single-stage ultra-marathon; training and racing

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    Background. In this Position Statement, the International Society of Sports Nutrition (ISSN) provides an objective and critical review of the literature pertinent to nutritional considerations for training and racing in single-stage ultra-marathon. Recommendations for Training. i) Ultra-marathon runners should aim to meet the caloric demands of training by following an individualized and periodized strategy, comprising a varied, food-first approach; ii) Athletes should plan and implement their nutrition strategy with sufficient time to permit adaptations that enhance fat oxidative capacity; iii) The evidence overwhelmingly supports the inclusion of a moderate-to-high carbohydrate diet (i.e., ~60% of energy intake, 5 – 8 g⸱kg−1·d−1) to mitigate the negative effects of chronic, training-induced glycogen depletion; iv) Limiting carbohydrate intake before selected low-intensity sessions, and/or moderating daily carbohydrate intake, may enhance mitochondrial function and fat oxidative capacity. Nevertheless, this approach may compromise performance during high-intensity efforts; v) Protein intakes of ~1.6 g·kg−1·d−1 are necessary to maintain lean mass and support recovery from training, but amounts up to 2.5 g⸱kg−1·d−1 may be warranted during demanding training when calorie requirements are greater; Recommendations for Racing. vi) To attenuate caloric deficits, runners should aim to consume 150 - 400 kcal⸱h−1 (carbohydrate, 30 – 50 g⸱h−1; protein, 5 – 10 g⸱h−1) from a variety of calorie-dense foods. Consideration must be given to food palatability, individual tolerance, and the increased preference for savory foods in longer races; vii) Fluid volumes of 450 – 750 mL⸱h−1 (~150 – 250 mL every 20 min) are recommended during racing. To minimize the likelihood of hyponatraemia, electrolytes (mainly sodium) may be needed in concentrations greater than that provided by most commercial products (i.e., >575 mg·L−1 sodium). Fluid and electrolyte requirements will be elevated when running in hot and/or humid conditions; viii) Evidence supports progressive gut-training and/or low-FODMAP diets (fermentable oligosaccharide, disaccharide, monosaccharide and polyol) to alleviate symptoms of gastrointestinal distress during racing; ix) The evidence in support of ketogenic diets and/or ketone esters to improve ultra-marathon performance is lacking, with further research warranted; x) Evidence supports the strategic use of caffeine to sustain performance in the latter stages of racing, particularly when sleep deprivation may compromise athlete safety
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