2,945 research outputs found
Bone Turnover Response to Acute Exercise with Varying Impact Levels: A preliminary investigation
International Journal of Exercise Science 8(2): 154-163, 2015. The purpose of this investigation was to determine if there are changes in metabolic markers of bone turnover within the 24-hour period following an acute bout of jogging or water exercise. Ten healthy females (22-30 yr.) underwent three trials with different ground impact forces: jogging, water aerobics and control. For the jogging and water aerobics trials, subjects exercised for 30 min at 60-70% of predicted maximal heart rate in addition to a 5 min warm up and cool down. For the control trial, subjects rested for 40 min, i.e., the total exercise time of the other trials. For each trial, blood samples were collected pre, immediately post, 1 hr. post, and 24 hr. post exercise. All samples were analyzed for levels of osteocalcin, bone specific alkaline phosphatase and cross-linked N telopeptides. A repeated-measure ANOVA was used to determine if there were differences between impact levels or over time. There were no significant differences over time, or between impact levels of exercise. Therefore these results indicate that healthy young women demonstrate no changes in bone turnover within 24 hr. of a single bout of exercise. Due to biochemical markers of bone turnover responding in a similar manner regardless of activity type, these findings suggest that water aerobics can be seen as a beneficial form of exercise for maintenance of bone density
A Preliminary Report on Unique Hail and Tornadic Storm Observations in Central Illinois and Eastern Indiana on 3 April 1974
published or submitted for publicationis peer reviewedOpe
Microspectrophotometric Analysis of Yellow Polyester Fiber Dye Loadings with Chemometric Techniques
Microspectrophotometry is a quick, accurate, and reproducible method to compare colored fibers for forensic purposes. Applying chemometric techniques to spectroscopic data can provide valuable information, especially when looking at a complex dataset. In this study, background subtracted and normalized visible spectra from ten yellow polyester exemplars dyed with different concentrations of the same dye ranging from 0.1% to 3.5% (w/w), were analyzed by agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and discriminant analysis (DA). Systematic changes in the wavelength of maximum absorption, peak shape and signal-to-background ratio were noted as dye loading increased. In general, classifying the samples into ten groups (one for each exemplar) had poor accuracy (i.e., 51%). However, classification was much more accurate (i.e., 96%) using three classes of fibers that were identified by AHC as having low (0.10–0.20 wt%), medium (0.40–0.75 wt%), and high (1.5–3.5 wt%) dye loadings. An external validation with additional fibers and data generated by independent analysts confirmed these findings. Lastly, it was also possible to discriminating pairs of exemplars with small differences in dye loadings as a simulation of questioned (Q) versus known (K) comparisons
Comparison of Methods to Assess Adiposity in Middle-to-Older Adult Women
Poster from the 2015 Food & Nutrition Conference & Expo. Poster Session: Professional Skills; Nutrition Assessment; Medical Nutrition Therapy
The long-term evolution of the spin, pulse shape, and orbit of the accretion-powered millisecond pulsar SAX J1808.4-3658
We present a 7 yr timing study of the 2.5 ms X-ray pulsar SAX J1808.4-3658,
an X-ray transient with a recurrence time of ~2 yr, using data from the Rossi
X-ray Timing Explorer covering 4 transient outbursts (1998-2005). We verify
that the 401 Hz pulsation traces the spin frequency fundamental and not a
harmonic. Substantial pulse shape variability, both stochastic and systematic,
was observed during each outburst. Analysis of the systematic pulse shape
changes suggests that, as an outburst dims, the X-ray "hot spot" on the pulsar
surface drifts longitudinally and a second hot spot may appear. The overall
pulse shape variability limits the ability to measure spin frequency evolution
within a given X-ray outburst (and calls previous nudot measurements of this
source into question), with typical upper limits of |nudot| < 2.5x10^{-14} Hz/s
(2 sigma). However, combining data from all the outbursts shows with high (6
sigma) significance that the pulsar is undergoing long-term spin down at a rate
nudot = (-5.6+/-2.0)x10^{-16} Hz/s, with most of the spin evolution occurring
during X-ray quiescence. We discuss the possible contributions of magnetic
propeller torques, magnetic dipole radiation, and gravitational radiation to
the measured spin down, setting an upper limit of B < 1.5x10^8 G for the
pulsar's surface dipole magnetic field and and Q/I < 5x10^{-9} for the
fractional mass quadrupole moment. We also measured an orbital period
derivative of Pdot = (3.5+/-0.2)x10^{-12} s/s. This surprising large Pdot is
reminiscent of the large and quasi-cyclic orbital period variation observed in
the so-called "black widow" millisecond radio pulsars, supporting speculation
that SAX J1808.4-3658 may turn on as a radio pulsar during quiescence. In an
appendix we derive an improved (0.15 arcsec) source position from optical data.Comment: 22 pages, 10 figures; accepted for publication in Ap
Correcting for the Effects of Interstellar Extinction
This paper addresses the issue of how best to correct astronomical data for
the wavelength-dependent effects of Galactic interstellar extinction. The main
general features of extinction from the IR through the UV are reviewed, along
with the nature of observed spatial variations. The enormous range of
extinction properties found in the Galaxy, particularly in the UV spectral
region, is illustrated. Fortunately, there are some tight constraints on the
wavelength dependence of extinction and some general correlations between
extinction curve shape and interstellar environment. These relationships
provide some guidance for correcting data for the effects of extinction.
Several strategies for dereddening are discussed along with estimates of the
uncertainties inherent in each method. In the Appendix, a new derivation of the
wavelength dependence of an average Galactic extinction curve from the IR
through the UV is presented, along with a new estimate of how this extinction
law varies with the parameter R = A(V)/E(B-V). These curves represent the true
monochromatic wavelength dependence of extinction and, as such, are suitable
for dereddening IR--UV spectrophotometric data of any resolution, and can be
used to derive extinction relations for any photometry system.Comment: To appear in PASP (January 1999) 14 pages including 4 pages of
figures Uses emulateapj style. PASP, in press (January 1999
Consistency and interpretation of changes in millimeter-scale cortical intrinsic curvature across three independent datasets in schizophrenia.
Several studies have sought to test the neurodevelopmental hypothesis of schizophrenia through analysis of cortical gyrification. However, to date, results have been inconsistent. A possible reason for this is that gyrification measures at the centimeter scale may be insensitive to subtle morphological changes at smaller scales. The lack of consistency in such studies may impede further interpretation of cortical morphology as an aid to understanding the etiology of schizophrenia. In this study we developed a new approach, examining whether millimeter-scale measures of cortical curvature are sensitive to changes in fundamental geometric properties of the cortical surface in schizophrenia. We determined and compared millimeter-scale and centimeter-scale curvature in three separate case-control studies; specifically two adult groups and one adolescent group. The datasets were of different sizes, with different ages and gender-spreads. The results clearly show that millimeter-scale intrinsic curvature measures were more robust and consistent in identifying reduced gyrification in patients across all three datasets. To further interpret this finding we quantified the ratio of expansion in the upper and lower cortical layers. The results suggest that reduced gyrification in schizophrenia is driven by a reduction in the expansion of upper cortical layers. This may plausibly be related to a reduction in short-range connectivity
New tunnel diode for zero-bias direct detection for millimeter-wave imagers
High-resolution passive millimeter wave imaging cameras require per pixel detector circuitry that is simple, has high sensitivity, low noise, and low power. Detector diodes that do not require bias or local oscillator input, and have high cutoff frequencies are strongly preferred. In addition, they must be manufacturable in large quantities with reasonable uniformity and reproducibility. Such diodes have not been obtainable for W-band and above. We are developing zero-bias square-law detector diodes based on InAs/Alsb/GaAlSb heterostructures which for the first time offer a cost-effective solution for large array formats. The diodes have a high frequency response and are relatively insensitive to growth and process variables. The large zero- bias non-linearity in current floor necessary for detection arises from interband tunneling between the InAs and the GaAlSb layers. Video resistance can be controlled by varying an Alsb tunnel barrier layer thickness. Our analysis shows that capacitance can be further decreased and sensitivity increased by shrinking the diode area, as the diode can have very high current density. DC and RF characterization of these devices and an estimate of their ultimate frequency performance in comparison with commercially available diodes are presented
Non–Destructive Imaging of Phytosulfokine Trafficking Using a Fiber–Optic Fluorescence Microscope
Plants secrete peptide ligands and use receptor signaling to respond to stress and control development. Understanding the signaling mechanisms and associated molecular trafficking is key to improving plant health and productivity for food, fiber and energy applications. However, one of the challenges to elucidating communication pathways in plants is to study the trafficking of molecules and signals iteratively and non-destructively.
This study focuses on using fiber-optic fluorescence microscopy to image live plants iteratively and non-destructively after delivering both labeled and unlabeled phytosulfokine (PSK) into the plant. PSK is a sulfated peptide hormone involved in the regulation of plant cell division and growth via specific receptors, PSKRs. It also plays a role in regulating how plants are able to tolerate stress conditions.
The microscope provides two-color (FITC/TRITC) optics and provides high-resolution (3–5 µm) epifluorescence micrographs via a 1-m coherent imaging fiber and a GRIN objective lens. To obtain high-quality images, the fiber was mounted either to a conventional upright microscope body equipped with a leaf compressor, or to a leaf clip with 5-axis positioning (X–Y–Z plus pitch and yaw) mounted on an extensible arm.
PSK and TAMRA-labelled PSK were delivered into the roots of various Arabidopsis thaliana genotypes (wt; receptor-deficient: pskr1/pskr2; and tagged receptor overproducing: PSKR1‑GFP), and their movement in roots and leaves was tracked with the fiber-optic fluorescence microscope.
Peptide trafficking was successfully observed in live plants non- destructively, confirming that PSK is mobile in both wt and receptor-deficient plants. Preliminary results suggest that the level of receptor PSKR1 may change in response to PSK, and that levels of PSKR1, PSKR2 or both may impact the trafficking of PSK. Understanding how PSK is trafficked in plants will offer insights into how we can improve plants health and productivity
Functional Social Support Moderates Stress on Depression in Individuals with CID during the COVID-19 Pandemic: A Two-Wave Study.
Depression is a common psychological experience for those living with a chronic illness and disease (CID). Social support (SS) can influence psychological health by regulating emotional functioning. The functional domain of SS refers to supportive exchange, including the emotional and instrumental functions. Public health measures during the COVID-19 pandemic include social distancing and isolation, which have impacted functional aspects of SS. The health risks of being isolated are comparable to the risks linked to obesity, blood pressure, and cigarette smoking. PURPOSE: To investigate the moderating effect of functional SS on the stress-depression relationship on individuals with CID during the COVID-19 pandemic. METHODS: Two waves of data were collected from a US sample: Apr. ’20: N = 321; Jun. ’20: N = 238. Participants completed the Patient Health Questionnaire–9 (depression symptoms), the Medical Outcomes Study–Social Support Survey–8 (perceived social support), and the Perceived Stress Scale–10 (perceived stress). For each wave of data, social support was entered as a moderator of the stress-depression relationship via multiple regression. RESULTS: The moderation models were estimated separately by wave. In the first wave, there was a negative but nonsignificant moderating effect (b = -0.19, p = .10) of social support on the stress-depression relationship (R2 = 51). In the second wave, the moderating relationship of social support doubled in magnitude (b = -0.30, p = .03, R2 = .57). During the COVID pandemic, functional social support weakened the association between stress and depression. CONCLUSION: Given the increased risk for social isolation and negative social exchange among people with CID during the COVID-19 pandemic, practitioners in rehabilitation psychology need to be informed about the potential implications of a lack of SS for the psychological health of the CID clients they work with. Drawing from the stress-buffering model and Lazarus et al.’s stress and coping theory (Lazarus, 1966; Lazarus & Folkman, 1984), our findings indicate that increased levels of perceived support can reduce the effects of stress on depression during the pandemic by contributing to fewer negative appraisals. Interventions targeting the particular functions of emotional (e.g., opportunities for emotional expression and venting) and instrumental (e.g., material aid) support could have immediate implications for facilitating rehabilitation outcomes (e.g., quality of life, interpersonal functioning, psychiatric symptomatology) during this public health crisis
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