Functionality of red blood cells after cryo-preservation.

One of the most common medical procedures performed in US hospitals is blood transfusions. Unfortunately, the red blood cells (RBCs) for transfusion have a limited shelf life after donation due to detrimental storage effects on morphological and biochemical properties. Inspired by nature, I am developing a biomimetics approach to preserve RBCs for long-term storage using compounds that occur in animals that have developed a natural propensity to survive in a frozen or desiccated state for decades. Trehalose was employed as a cryoprotective agent when added to the extracellular freezing solution. The highest percent of RBCs with intact membranes after freezing and thawing was obtained using a cryopreservation solution comprised of 250 million RBCs/mL, 300 mM trehalose, 100 mM NaCl, in 20 mM HEPES buffer, pH 7.1. Under these conditions RBCs with intact membranes were recovered at 86 ± 12%. I have demonstrated the effectiveness and feasibility of using trehalose as a cryoprotective agent, and morphological intact RBCs were recovered after freezing and thawing with low cellular loss

The alchemy of ideas

This article presents an assessment of the power of ideas and their role in initiating change and progress. The enormous potential cascade effect is illustrated by examining the movement of Modernism in the arts. Next, the immense scope and capabilities of the modern scientific endeavor—with robotic space exploration at the scale of 10⁹ meters at one extreme and the wonders of nanoscience at the scale of 10⁻⁹ m at the other—are examined. The attitudes and philosophies of neurological surgery are related to those involved in the Modernist movement and placed on the defined scale of contemporary scientific activity

Does Body Mass Index Influence the Physiological and Perceptual Demands Associated with Defensive Tactics Training in State Patrol Officers?

International Journal of Exercise Science 11(6): 319-330, 2018. The purpose of this investigation was to determine the physiological and perceptual demands associated with defensive tactics (DEFTAC) training among state patrol officers of different BMI (body mass index) categories. Twenty-four male state patrol officers (n = 24, age 36.00 + 7.86 yrs) voluntarily agreed to participate in data collection during a DEFTAC gauntlet. Anthropometric information (height (HT) 182.19 + 7.43 cm and weight (WT) 96.31 + 17.45 kg), body mass index (BMI), peak and average heart rates, duty weight, BLa, and RPE, were recorded. Officers were then divided into two-groups (Healthy BMI (BMI ≤ 25), n = 12, Overweight (BMI ≥ 25), n = 12). Analyses of covariance (ANCOVAs) were conducted to determine the effect of BMI on the outcome variables. Furthermore, a Pearson’s product-moment correlation coefficient was also conducted to determine if significant relationships between RPE, BLa, and HR existed between groups. Significant mean score differences between healthy and overweight officers were found in measures of age [t(22) 4.12, p\u3c 0.01, R2 = .44], and weight of duty gear [t(21) 3.96, p\u3c0.01, R2 = .33]. When used as a covariate, age also predicted average HR% [ F(1, 21) = 6.19, p \u3c .05, partial η2 = .24]. Significant relationships were found in the healthy group between RPE and DEFTAC time, DEFTAC time and score, as well as score and post BLa. Significant relationships for the overweight group between peak (HR) percentage and post BLa, peak (HR) percentage and RPE, DEFTAC time and duty weight, and between weight and DEFTAC time. The results of this study suggest that overweight officers may have lower DEFTAC scores when compared to their healthy counterparts. Based on the results, it seems reasonable to compare physiological variables from this population to those from combative sports as well as for officers to achieve and maintain a healthy BMI value in order to improve individual DEFTAC performance

Acupuncture and Chiropractic Care: Utilization and Electronic Medical Record Capture

Objectives: To describe acupuncture and chiropractic use among patients with chronic musculoskeletal pain (CMP) at a health maintenance organization, and explore issues of benefit design and electronic medical record (EMR) capture. Study Design: Cross-sectional survey. Methods: Kaiser Permanente members meeting EMR diagnostic criteria for CMP were invited to participate. The survey included questions about self-identified presence of CMP, use of acupuncture and chiropractic care, use of ancillary self-care modalities, and communication with conventional medicine practitioners. Analysis of survey data was supplemented with a retrospective review of EMR utilization data. Results: Of 6068 survey respondents, 32% reported acupuncture use, 47% reported chiropractic use, 21% used both, and 42% used neither. For 25% of patients using acupuncture and 43% of those using chiropractic care, utilization was undetected by the EMR. Thirty-five percent of acupuncture users and 42% of chiropractic users did not discuss this care with their health maintenance organization (HMO) clinicians. Among chiropractic users, those accessing care out of plan were older (P \u3c.01), were more likely to use long-term opioids (P = .03), and had more pain diagnoses (P = .01) than those accessing care via clinician referral or self-referral. For acupuncture, those using the clinician referral mechanism exhibited these same characteristics. Conclusions: A majority of participants had used acupuncture, chiropractic care, or both. While benefit structure may materially influence utilization patterns, many patients with CMP use acupuncture and chiropractic care without regard to their insurance coverage. A substantial percentage of acupuncture and chiropractic use thus occurs beyond detection of EMR systems, and many patients do not report such care to their HMO clinicians

Oriented texture detection: Ideal observer modelling and classification image analysis

Perception of visual texture flows contributes to object segmentation, shape perception, and object recognition. To better understand the visual mechanisms underlying texture flow perception, we studied the factors limiting detection of simple forms of texture flows composed of local dot dipoles (Glass patterns) and related stimuli. To provide a benchmark for human performance, we derived an ideal observer for this task. We found that human detection thresholds were 8.0 times higher than ideal. We considered three factors that might account for this performance gap: (1) false matches between dipole dots (correspondence errors), (2) loss of sensitivity with increasing eccentricity, and (3) local orientation bandwidth. To estimate the effect of correspondence errors, we compared detection of Glass patterns with detection of matched line-segment stimuli, where no correspondence uncertainty exists. We found that eliminating correspondence errors reduced human thresholds by a factor of 1.8. We used a novel form of classification image analysis to directly estimate loss of sensitivity with eccentricity and local orientation bandwidth. Incorporating the eccentricity effects into the ideal observer model increased ideal thresholds by a factor of 2.9. Interestingly, estimated orientation bandwidth increased ideal thresholds by only 8%. Taking all three factors into account, human thresholds were only 58% higher than model thresholds. Our findings suggest that correspondence errors and eccentricity losses account for the great majority of the perceptual loss in the visual processing of Glass patterns. Introduction Detection of oriented texture is an important problem, as it partially underlies our ability to segment figure from ground and perceive three-dimensional shape The problem of detecting local orientations has been a central focus of neurophysiological research on the visual processing of Glass patterns. How does the brain extract these weak orientation signals from Glass-pattern dipoles while suppressing spurious responses? To resolve this continuing debate, a better understanding of perceptual limits in the detection of Glass patterns is required. Early work focused largely on how correspondence errors alone limit perception of Glass patterns. For example, In order to more completely understand the perceptual factors determining the detection of texture flows, we conducted a new series of human psychophysical experiments using both linear Glass patterns Methods Observers Three experienced psychophysical observers participated in the experiments. Two of the observers (DN and YM) were naive to the purpose of the experiments, and the third observer (CFO) was one of the authors. All observers had normal, or corrected-to-normal, visual acuity. Apparatus Stimuli were generated using an Apple Power Macintosh G5 computer and MATLAB version 7.1 and were displayed on a 15-in. Apple colour monitor, at a frame rate of 85 Hz and a resolution of 1024 Â 768 pixels. Observers viewed the monitor screen binocularly at a distance of 70 cm in a dimly lit observation room. The monitor was gamma corrected by measuring the luminance of each RGB level with a Minolta LS-100 photometer, and then generating independent lookup tables for the red, green, and blue guns such that the screen luminance was linearized as a function of the grey level. Observers indicated their responses by pressing buttons on a standard keyboard. Stimuli Glass patterns Each linear Glass pattern As oblique Glass patterns have been found to result in better detection performance than horizontal or vertical (inverse oblique effect: Wilson, Loffler, Wilkinson, & Thistlethwaite, 2001), we ran separate experiments using horizontal (0 deg; see Line patterns One possible factor underlying perceptual loss in Glass pattern detection is correspondence errors or errors in orientation detection arising from random correlations of local dots. This problem can be eliminated by replacing dipoles with oriented line segments. Dakin (1997) showed that while detection of Glass patterns deteriorates beyond an optimal dipole length, detection of line patterns asymptotically improves with line length. Line patterns may also be useful in assessing information loss due to orientation tuning (Orientation loss section). For these reasons, we conducted our experiments also with line patterns Procedure A Yes/No detection task was used. On each trial, the observer was presented with a central fixation display for 1 s, followed by the target stimulus, centrally displayed for 165 ms (14 frames at 85 Hz), sufficiently brief to eliminate eye movements. The target stimulus on each trial was randomly either an oriented texture with a proportion of signal and noise elements (signal-plus-noise trial) or a pattern consisting of noise elements only (noise trial). The observer indicated by button press whether a presentation contained an oriented texture. The observer was notified of a correct or incorrect choice by an audible tone immediately after each decision. Observers were tested, in a randomized order, in 12 conditions consisting of all combinations of three Journal of Vision (The exact number of blocks performed by each observer and for each condition varied slightly.) At the beginning of the first block, the initial signal level was set to 100 signal elements (50% signal) and the remaining 100 elements were noise elements. The initial signal level of each subsequent block was set to the maximum likelihood estimate of the detection threshold obtained from the previous block of the same condition. The mean detection threshold was calculated by averaging the maximum likelihood estimates of the detection thresholds obtained from all blocks for the same condition. Ideal observer modelling Since the retinal location of oriented elements is irrelevant to the task, the histogram of element orientations In addition to knowledge of the signal level n s , we assume that the ideal observer knows that the prior odds of signal present/absent is 50/50 and that the objective is to maximize proportion correct, consistent with a uniform reward for hits and correct rejects or equivalently a uniform loss for false positives and misses. With this knowledge, and an observed number of elements n 0 at the known signal orientation, the ideal observer reports the signal present if and only if this is the more likely event. Letting H 0 and H 1 denote the signal-absent and signalpresent events, respectively, the decision rule can be written as Calculating the likelihood ratio is straightforward, since for both signal-present and signal-absent trials, n 0 follows a binomial distribution: where p E = 1/n E is the probability that a single noise element will have a particular orientation, given n E discrete stimulus orientations (n E = 6, 12, or 24 in our experiments). The decision rule in Equation 1 then determines the ideal criterion n 0 V: In other words, n 0 Vis the minimum number of elements in the signal orientation for which the likelihood ratio equals or exceeds 1. Given the optimal criterion n 0 V as a function of signal level n s , the proportion of correct responses p c for every possible signal level n s Z [0, I, N] (where N = 200) can be computed as the average of the hit rate p Hit and correctreject rate p CR : where Journal of Vision Given the proportion of correct responses p c (n s ) for every integer signal level n s Z [0, I, N], we compute the ideal threshold n s V for 75% correct performance by linear interpolation. Results Journal of Vision Our first observation is that observers varied significantly in how well they performed the oriented texture detection task. This may, in part, be due to individual differences in the parameters of detection mechanisms that we shall attempt to estimate in this paper; this possibility is reinforced by the significant interactions between observer and the stimulus parameters. For this reason, much of our subsequent analysis will be within subjects. Our second observation is that, for all three observers, Glass patterns have significantly higher detection thresholds than line patterns, by a factor of 1.8 on average. This finding confirms that line patterns produce a stronger texture flow than Glass patterns, possibly due to the absence of correspondence errors in line patterns. Our third observation is that, for two of our three observers, thresholds are significantly lower for oblique patterns than for horizontal patterns, consistent with previous findings Journal of Vision (2011) 11(8):16, 1-20 Or & Elder 7 Downloaded from jov.arvojournals.org on 06/30/2019 significant (p = 0.57) for the third observer. This finding suggests that the inverse oblique effect may only hold for a subset of the population, although clearly a larger sample size is required to substantiate this claim. Our fourth observation is that there is a general decline in thresholds as the number of orientations in the stimulus is increased, statistically significant in all three observers (p G 0.04). Note that the decline in thresholds is predicted by the ideal observer model and reflects the decline in the number of noise elements at the signal orientation as the number of orientations in the stimulus increases. Our final observation is that thresholds for the ideal observer are considerably lower than for human observers, even when correspondence errors have been accounted for (using line patterns). Clearly, there are other important sources of information loss in the detection of oriented textures: we now set out to identify and quantify these losses. Classification image analysis Prior work has suggested that the detection of oriented textures is limited by (1) decline in sensitivity with eccentricity (eccentricity loss; Here, we use a classification image technique Eccentricity loss Background It is well known that visual performance generally decreases with retinal eccentricity due to optical It is to be expected that the decay in sensitivity with eccentricity will limit the detection of oriented textures. However, the rate of decay is disputed. While Here, we used the classification image technique to directly measure observers' sensitivity to orientation information at different spatial locations relative to fixation. The decay in element sensitivity with eccentricity was estimated from the resulting sensitivity function. Methods A sensitivity function for signal-absent trials was determined by comparing the eccentricities of noise elements at the signal orientation in false-alarm and correct-reject trials. In particular, a sensitivity estimate can be computed by accumulating noise elements into discrete eccentricity bins for false-alarm and correct-reject trials separately, and then differencing the normalized bins to produce an empirical estimate of the sensitivity function C r at discrete eccentricity bins i: where n FA is the number of false-alarm trials, n CR is the number of correct-reject trials, N FA (i) is the number of elements falling in eccentricity bin i over all false-alarm trials, and N CR (i) is the number of elements falling in eccentricity bin i over all correct-reject trials. Note that Equation 8 can be rewritten as Journal of Vision and N i is the number of elements falling in bin i over all (signal-absent) trials. This empirical estimate of the sensitivity function will only be accurate if each bin contains (roughly) the same number of elements. Since the expected number of elements falling within a fixed tolerance of a given eccentricity r increases as r 2 , the bin width is made to decrease as ffiffi r p such that the expected number of elements is the same across the bins. It would be nice to capture this falloff in sensitivity with a simple parametric model. Prior studies have suggested an exponential falloff in sensitivity with eccentricity, for a range of perceptual tasks where r is the eccentricity of an element, defined as the angular deviation of the element's midpoint from fixation, and r 0 is the space constant for the falloff. While our binning method provides a good visualization of the falloff in sensitivity C r (r) with eccentricity r, a least-squares fit of our modelĈ r (r) directly to this empirical sensitivity function C r (r) is sensitive to the choice of the bin width. We can eliminate this dependence by using one bin per oriented texture element, centring each on the eccentricity of that element, and making the bin widths so small that they each encompass only one point. It is important to note that there may be gaps and overlaps between the bins, but this is not a problem, since our goal is only to estimate the sensitivity at a discrete number of r values, not to estimate a probability density. Under these conditions, the number of bins is equal to the total number of elements and the estimated sensitivity at the ith bin is given by C r ðiÞ ¼ w ij ; with w ij defined as in Equations 9 and 10. Now a leastsquares fit of the modelĈ r (r) to the data can be computed by minimizing ðĈ r ðiÞ j C r ðiÞÞ where I FA and I CR are the index sets for all noise elements in the false-alarm and correct-reject trials, respectively. We minimize Equation 13 over A r and r 0 using a standard gradient descent method (MATLAB fminsearch). We report only the results for r 0 , since A r is an arbitrary scaling constant. The fit of the exponential model to the data using this method is good, yielding parameters similar to those estimated by fitting histogram

Late-Onset Erythropoietic Porphyria Caused by a Chromosome 18q Deletion in Erythroid Cells

The erythropoietic porphyrias, erythropoietic protoporphyria and congenital erythropoietic porphyria, result from germline mutations in the ferrochelatase gene and uroporphyrinogen III synthase gene, respectively. Both conditions normally present in childhood but rare cases with onset past the age of 40 y have been reported. Here we show that late-onset erythropoietic protoporphyria can be caused by deletion of the ferrochelatase gene in hematopoietic cells with clonal expansion as part of the myelodysplastic process. This is the first direct demonstration of porphyria produced by an acquired molecular defect restricted to one tissue. Some other cases of late-onset erythropoietic porphyria may be explained by a similar mechanism

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack <25% through wall' in 2002, was clearly shown not to be a crack. Additionally, examination of a new area immediately adjacent to other cracks along a vertical weld revealed three new cracks. It is not known when these new cracks formed as they could very well have been present in 2002 as well. Therefore, a total of twelve cracks were evaluated during the re-examination. Comparison of the crack lengths measured in 2002 and 2007 revealed that crack growth had occurred in four of the nine previously measured cracks. The crack length extension ranged from 0.25 to 1.8 inches. However, in all cases the cracks still remained within the residual stress zone (i.e., within two to three inches of the weld). The impact of the cracks that grew on the future service of Tank 15 was re-assessed. API-579 crack instability calculations were again performed, based on expected future service conditions and trended crack growth rates for the future tank service cycle. The analysis showed that the combined hydrostatic and weld residual stresses do not drive the identified cracks to instability. This tank expected to be decommissioned in the near future. However, if these plans are delayed, it was recommended that a third examination of selected cracks in the tank be performed in 2014

Effects of erythropoietin therapy on the lipid profile in end-stage renal failure

Effects of erythropoietin therapy on the lipid profile in end-stage renal failure. To evaluate the effects of erythropoietin (EPO) therapy on the lipid profile in end-stage renal failure, we undertook a prospective study in patients on both hemodialysis (HD) and continuous ambulatory peritoneal dialysis (CAPD). One hundred and twelve patients (81 HD, 31 CAPD) were enrolled into the study. Lipid parameters [that is, total cholesterol and the LDL and HDL subfractions, triglycerides, lipoprotein (a), apoproteins A and B], full blood count, iron studies, B12, folate, blood urea, aluminium and serum parathyroid hormone were measured prior to commencement of EPO therapy. Ninety-five patients were reassessed 5.2 ± 0.3 (mean ± SEM) months later and 53 patients underwent a further assessment 13.1 ± 0.6 months after the commencement of EPO, giving an overall follow-up of 10.0 ± 0.6 months in 95 patients. As expected, EPO treatment was associated with an increase in hemoglobin (7.7 ± 0.1 vs. 9.9 ± 0.2 g/dl; P < 0.001) and a decrease in ferritin (687 ± 99 vs. 399 ± 69 µg/liter; P < 0.01). A significant fall in total cholesterol occurred (5.8 ± 0.1 vs. 5.4 ± 0.2 mmol/liter; P < 0.05) in association with a fall in apoprotein B (1.15 ± 0.04 vs. 1.04 ± 0.06; P < 0.05) and serum triglycerides (2.26 ± 0.14 vs. 1.99 ± 0.21; P < 0.05) during the course of the study. Other lipid parameters did not change, although there was a trend towards improvement. These changes correlated with the increase in Hb (P < 0.001 in each case), and the reduction in ferritin for total cholesterol (P < 0.02), LDL cholesterol (P < 0.03), and to a lesser extent apoprotein B (P < 0.07). No difference was observed in patients using maintenance HD or CAPD, and similar trends were observed in male and female patients. Improvements in the lipid profile occurred independently of the time on dialysis prior to the commencement of EPO. We conclude that EPO treatment is associated with alterations in the lipid profile which may suggest a long-term improvement in the vascular morbidity of chronic renal failure. The causes of the improved lipids are not addressed by this study and may be equally due to a direct or secondary benefit of EPO therapy

Overview of SnowEx Year 1 Activities

SnowEx is a multi-year airborne snow campaign with the primary goal of addressing the question: How much water is stored in Earths terrestrial snow-covered regions? Year 1 (2016-17) focused on the distribution of snow-water equivalent (SWE) and the snow energy balance in a forested environment. The year 1 primary site was Grand Mesa and the secondary site was the Senator Beck Basin, both in western, Colorado, USA. Nine sensors on five aircraft made observations using a broad range of sensing techniques, active and passive microwave, and active and passive optical infrared to determine the sensitivity and accuracy of these potential satellite remote sensing techniques, along with models, to measure snow under a range of forest conditions. SnowEx also included an extensive range of ground truth measurements in-situ manual samples, snow pits, ground based remote sensing measurements, and sophisticated new techniques. A detailed description of the data collected will be given and some preliminary results will be presented

Randomized trial of tapas acupressure technique for weight loss maintenance

<p>Abstract</p> <p>Background</p> <p>Obesity is an urgent public health problem, yet only a few clinical trials have systematically tested the efficacy of long-term weight-loss maintenance interventions. This randomized clinical trial tested the efficacy of a novel mind and body technique for weight-loss maintenance.</p> <p>Methods</p> <p>Participants were obese adults who had completed a six-month behavioral weight-loss program prior to randomization. Those who successfully lost weight were randomized into either an experimental weight-loss maintenance intervention, Tapas Acupressure Technique (TAT^®), or a control intervention comprised of social-support group meetings (SS) led by professional facilitators. TAT combines self-applied light pressure to specific acupressure points accompanied by a prescribed sequence of mental steps. Participants in both maintenance conditions attended eight group sessions over six months of active weight loss maintenance intervention, followed by an additional 6 months of no intervention. The main outcome measure was change in weight from the beginning of the weight loss maintenance intervention to 12 months later. Secondary outcomes were change in depression, stress, insomnia, and quality of life. We used analysis of covariance as the primary analysis method. Missing values were replaced using multiple imputation.</p> <p>Results</p> <p>Among 285 randomized participants, 79% were female, mean age was 56 (standard deviation (sd) = 11), mean BMI at randomization was 34 (sd = 5), and mean initial weight loss was 9.8 kg (sd = 5). In the primary outcome model, there was no significant difference in weight regain between the two arms (1.72 kg (se 0.85) weight regain for TAT and 2.96 kg (se 0.96) weight regain for SS, p < 0.097) Tests of between- arm differences for secondary outcomes were also not significant. A secondary analysis showed a significant interaction between treatment and initial weight loss (p < .036), with exploratory <it>post hoc </it>tests showing that greater initial weight loss was associated with more weight regain for SS but less weight regain for TAT.</p> <p>Conclusions</p> <p>The primary analysis showed no significant difference in weight regain between TAT and SS, while secondary and post hoc analyses indicate direction for future research.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00526565">NCT00526565</a></p