Iconic Memory and Aging: Effects of Stimulus Duration, Stimulus Contrast, and Inter-Stimulus Interval

Previous studies have shown that old adults perform more poorly on the classic Sperling partial report task than do young adults. In this study, the researcher examined whether age differences in performance could be accounted for by changes in visual and perceptual ability. Eighteen old adults (M = 70 years) and 18 young adults (M = 22 years) were administered whole and partial report trials with stimulus durations of 150 ms; a second group of 18 young adults was tested with stimulus durations of 30 ms. Stimuli were presented at two levels of contrast (98 and 44 percent) and the partial report trials included four cue-delay conditions (0, 50, 150, 300 ms). Measures of processing speed, visual acuity, contrast sensitivity and word fluency were collected as predictor variables. Old adults demonstrated partial report superiority at the 0 ms cue-delay, but fell to whole report levels at longer delays. Young participants demonstrated partial report superiority across all cue-delays, regardless of stimulus duration. Letter recall was not influenced by stimulus contrast. Predictor variables, except word fluency, accounted for approximately equal amounts of age-related variability. Results suggest that factors such as processing speed and visual ability, rather than changes in iconic memory, may be responsible for age differences in partial report performance

Automated Estimation of Plasma Temperature and Density from Emission Spectroscopy

This paper introduces a novel approach for automated estimation of plasma temperature and density using emission spectroscopy, integrating Bayesian inference with sophisticated physical models. We provide an in-depth examination of Bayesian methods applied to the complexities of plasma diagnostics, supported by a robust framework of physical and measurement models. Our methodology is validated through experimental observations, focusing on individual and sequential shot analyses. The results demonstrate the effectiveness of our approach in enhancing the accuracy and reliability of plasma parameter estimation, marking a significant advancement in the field of emission spectroscopy for plasma diagnostics. This study not only offers a new perspective in plasma analysis but also paves the way for further research and applications in nuclear instrumentation and related domains.Comment: 25 pages, 8 figure

Understanding Diabetes-Related Distress Characteristics and Psychosocial Support Preferences of Urban African American Adults Living With Type 2 Diabetes: A Mixed-Methods Study

Purpose The purpose of this study is to understand diabetes-related distress (DRD) characteristics and identify psychosocial support preferences of urban African American adults living with type 2 diabetes (T2DM). Methods A 2-phase, mixed-methods sequential explanatory study design was used to gather data. In phase 1, a purposive sample of participants (N = 155) was recruited and asked to complete a written survey. The Diabetes Distress Scale (DDS17) was used to assess DRD, including subscales—emotional burden (EB), regimen distress (RD), interpersonal distress (ID), and physician distress (PD). In phase 2, a subset of phase 1 participants (N = 23) volunteered to attend 1 of 4 gender-stratified follow-up focus groups to contextualize the quantitative survey results. Results Survey findings indicate that on average, participants had moderate levels of DRD (aggregate), RD, and EB but had low ID and PD. During follow-up focus groups, participants described RD and EB as their primary distress types and emphasized that clinicians should prioritize the mental health aspects of T2DM similarly to its physical aspects. Participants expressed a desire for culturally appropriate peer support groups as a psychosocial support resource for distress coping and specifically requested the development of gender-stratified groups and groups for young adults. Conclusions Results support the need to screen for and address diabetes-related distress among African American patients with T2DM. Findings also inform the development of culturally appropriate psychosocial support resources to facilitate diabetes-related distress coping

Compact ring-based X-ray source with on-orbit and on-energy laser-plasma injection

We report here the results of a one week long investigation into the conceptual design of an X-ray source based on a compact ring with on-orbit and on-energy laser-plasma accelerator. We performed these studies during the June 2016 USPAS class "Physics of Accelerators, Lasers, and Plasma..." applying the art of inventiveness TRIZ. We describe three versions of the light source with the constraints of the electron beam with energy $1\,\rm{GeV}$ or $3\,\rm{GeV}$ and a magnetic lattice design being normal conducting (only for the $1\,\rm{GeV}$ beam) or superconducting (for either beam). The electron beam recirculates in the ring, to increase the effective photon flux. We describe the design choices, present relevant parameters, and describe insights into such machines.Comment: 4 pages, 1 figure, Conference Proceedings of NAPAC 201

De novo design of bioactive protein switches.

Allosteric regulation of protein function is widespread in biology, but is challenging for de novo protein design as it requires the explicit design of multiple states with comparable free energies. Here we explore the possibility of designing switchable protein systems de novo, through the modulation of competing inter- and intramolecular interactions. We design a static, five-helix 'cage' with a single interface that can interact either intramolecularly with a terminal 'latch' helix or intermolecularly with a peptide 'key'. Encoded on the latch are functional motifs for binding, degradation or nuclear export that function only when the key displaces the latch from the cage. We describe orthogonal cage-key systems that function in vitro, in yeast and in mammalian cells with up to 40-fold activation of function by key. The ability to design switchable protein functions that are controlled by induced conformational change is a milestone for de novo protein design, and opens up new avenues for synthetic biology and cell engineering

Co-Expression of VEGF and IL-6 Family Cytokines is Associated with Decreased Survival in HER2 Negative Breast Cancer Patients: Subtype-Specific IL-6 Family Cytokine-Mediated VEGF Secretion

Breast cancer cell-response to inflammatory cytokines such as interleukin-6 (IL-6) and oncostatin M (OSM) may affect the course of clinical disease in a cancer subtype-dependent manner. Furthermore, vascular endothelial growth factor A (VEGF) secretion induced by IL-6 and OSM may also be subtype-dependent. Utilizing datasets from Oncomine, we show that poor survival of invasive ductal carcinoma (IDC) breast cancer patients is correlated with both high VEGF expression and high cytokine or cytokine receptor expression in tumors. Importantly, epidermal growth factor receptor-negative (HER2-), but not HER2-positive (HER2+), patient survival is significantly lower with high tumor co-expression of VEGF and OSM, OSMRβ, IL-6, or IL-6Rα compared to low co-expression. Furthermore, assessment of HER2- breast cancer cells in vitro identified unique signaling differences regulating cytokine-induced VEGF secretion. The levels of VEGF secretion were analyzed by ELISA with siRNAs for hypoxia inducible factor 1 α (HIF1α) and signal transducer and activator of transcription 3 (STAT3). Specifically, we found that estrogen receptor-negative (ER-) MDA-MB-231 cells respond only to OSM through STAT3 signaling, while ER+ T47D cells respond to both OSM and IL-6, though to IL-6 to a lesser extent. Additionally, in the ER+ T47D cells, OSM signals through both STAT3 and HIF1α. These results highlight that the survival of breast cancer patients with high co-expression of VEGF and IL-6 family cytokines is dependent on breast cancer subtype. Thus, the heterogeneity of human breast cancer in relation to IL-6 family cytokines and VEGF may have important implications in clinical treatment options, disease progression, and ultimately patient prognosis

Dilepton mass spectra in p plus p collisions at root s=200 GeV and the contribution from open charm

PHENIX has measured the electron-positron pair mass spectrum from 0 to 8 GeV/c(2) in p + p collisions at root s = 200 GeV. The contributions from light meson decays to e(+)e(-) pairs have been determined based on measurements of hadron production cross sections by PHENIX. Within the systematic uncertainty of similar to 20% they account for all e(+)e(-) pairs in the mass region below similar to 1 GeV/c(2). The e(+)e(-) pair yield remaining after subtracting these contributions is dominated by semileptonic decays of charmed hadrons correlated through flavor conservation. Using the spectral shape predicted by PYTHIA, we estimate the charm production cross section to be 544 +/- 39(stat) +/- 142(syst) +/- 200(model) pb. which is consistent with QCD calculations and measurements of single leptons by PHENIX

Inclusive cross section and double helicity asymmetry for pi(0) production in p+p collisions at root s=200 GeV: Implications for the polarized gluon distribution in the proton

The PHENIX experiment presents results from the Relativistic Heavy Ion Collider 2005 run with polarized proton collisions at root s=200 GeV, for inclusive pi(0) production at midrapidity. Unpolarized cross section results are given for transverse momenta p(T)=0.5 to 20 GeV/c, extending the range of published data to both lower and higher p(T). The cross section is described well for p(T)\u3c 1 GeV/c by an exponential in p(T), and, for p(T)\u3e 2 GeV/c, by perturbative QCD. Double helicity asymmetries A(LL) are presented based on a factor of 5 improvement in uncertainties as compared to previously published results, due to both an improved beam polarization of 50%, and to higher integrated luminosity. These measurements are sensitive to the gluon polarization in the proton. Using one representative model of gluon polarization it is demonstrated that the gluon spin contribution to the proton spin is significantly constrained

Measurement of High-p(T) single electrons from heavy-flavor decays in p+p collisions at root s=200 GeV

The momentum distribution of electrons from decays of heavy flavor (charm and bottom) for midrapidity |y|\u3c 0.35 in p+p collisions at s=200 GeV has been measured by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider over the transverse momentum range 0.3 \u3c p(T)\u3c 9 GeV/c. Two independent methods have been used to determine the heavy-flavor yields, and the results are in good agreement with each other. A fixed-order-plus-next-to-leading-log perturbative QCD calculation agrees with the data within the theoretical and experimental uncertainties, with the data/theory ratio of 1.71 +/- 0.02(stat)+/- 0.18(sys) for 0.3 \u3c p(T)\u3c 9 GeV/c. The total charm production cross section at this energy has also been deduced to be sigma(cc)=567 +/- 57(stat)+/- 193(sys) mu b

J/psi production in root s(NN)=200 GeV Cu+Cu collisions

Yields for J/psi production in Cu+Cu collisions at root s(NN) = 200 GeV have been measured over the rapidity range |y|\u3c 2.2 and compared with results in p+p and Au+Au collisions at the same energy. The Cu+Cu data offer greatly improved precision over existing Au+Au data for J/psi production in collisions with small to intermediate numbers of participants, in the range where the quark-gluon plasma transition threshold is predicted to lie. Cold nuclear matter estimates based on ad hoc fits to d+Au data describe the Cu+Cu data up to N-part similar to 50, corresponding to a Bjorken energy density of at least 1.5 GeV/fm(3)