Ground performance of the High-Energy Focusing Telescope (HEFT) attitude control system

The High Energy Focusing Telescope (HEFT) is a balloon-borne, hard x-ray/gamma ray (20-70 keV) astronomical experiment. HEFT's 10 arcminute field of view and 1 arcminute angular resolution place challenging demands on its attitude control system (ACS). A microprocessor-based ACS has been developed to manage target acquisition and sidereal tracking. The ACS consists of a variety of sensors and actuators, with provisions for 2-way ground communication, all controlled by an on-board computer. Ground based pointing performance measurements indicate 1σ jitter of 7" and gyro drift rates of <1" s^(-1). Jitter is expected to worsen in the flight environment, but star tracker data are expected to reduce drift rates significantly, enabling a predicted 1σ absolute attitude determination of ≥4.7". HEFT is scheduled for flight in Spring 2004

Who's my little monkey? Effects of infant-directed speech on visual retention in infant rhesus macaques

Both human and nonhuman primate adults use infant-directed facial and vocal expressions across many contexts when interacting with infants (e.g. feeding, playing). This infant-oriented style of communication, known as infant-directed speech (IDS), seems to benefit human infants in numerous ways, including facilitating language acquisition. Given the variety of contexts in which adults use IDS, we hypothesized that IDS supports learning beyond the linguistic domain and that these benefits may extend to nonhuman primates. We exposed 2.5-month-old rhesus macaque infants (N=15) to IDS, adult-directed speech (ADS), and a nonsocial control (CTR) during a video presentation of unrelated stimuli. After a 5- or 60-minute delay, infants were shown the familiar video side-by-side with a novel video. Infants exhibited a novelty preference after the 5-minute delay, but not after the 60-minute delay, in the ADS and CTR conditions, and a novelty preference in the IDS condition only after the 60-minute delay. These results are the first to suggest that exposure to IDS affects infants’ long-term memory, even in non-linguistic animals

A Mechanistic Study of the Association Between Symbolic Approximate Arithmetic Performance and Basic Number Magnitude Processing Based on Task Difficulty

Two types of number magnitude processing – semantic and spatial – are significantly correlated with children’s arithmetic performance. However, it remains unclear whether these abilities are independent predictors of symbolic approximate arithmetic performance. The current study addressed this question by assessing 86 kindergartners (mean age of 5 years and 7 months) on semantic number processing (number comparison task), spatial number processing (number line estimation task), and symbolic approximate arithmetic performance with different levels of difficulty. The results showed that performance on both tasks of number magnitude processing was significantly correlated with symbolic approximate arithmetic performance, but the strength of these correlations was moderated by the difficulty level of the arithmetic task. The simple symbolic approximate arithmetic task was equally related to both tasks. In contrast, for more difficult symbolic approximate arithmetic tasks, the contribution of number comparison ability was smaller than that of the number line estimation ability. These results indicate that the strength of contribution of the different types of numerical processing depends on the difficulty of the symbolic approximate arithmetic task

Circulating microRNAs in sera correlate with soluble biomarkers of immune activation but do not predict mortality in ART treated individuals with HIV-1 infection: A case control study

Introduction: The use of anti-retroviral therapy (ART) has dramatically reduced HIV-1 associated morbidity and mortality. However, HIV-1 infected individuals have increased rates of morbidity and mortality compared to the non-HIV-1 infected population and this appears to be related to end-organ diseases collectively referred to as Serious Non-AIDS Events (SNAEs). Circulating miRNAs are reported as promising biomarkers for a number of human disease conditions including those that constitute SNAEs. Our study sought to investigate the potential of selected miRNAs in predicting mortality in HIV-1 infected ART treated individuals. Materials and Methods: A set of miRNAs was chosen based on published associations with human disease conditions that constitute SNAEs. This case: control study compared 126 cases (individuals who died whilst on therapy), and 247 matched controls (individuals who remained alive). Cases and controls were ART treated participants of two pivotal HIV-1 trials. The relative abundance of each miRNA in serum was measured, by RTqPCR. Associations with mortality (all-cause, cardiovascular and malignancy) were assessed by logistic regression analysis. Correlations between miRNAs and CD4+ T cell count, hs-CRP, IL-6 and D-dimer were also assessed. Results: None of the selected miRNAs was associated with all-cause, cardiovascular or malignancy mortality. The levels of three miRNAs (miRs -21, -122 and -200a) correlated with IL-6 while miR-21 also correlated with D-dimer. Additionally, the abundance of miRs -31, -150 and -223, correlated with baseline CD4+ T cell count while the same three miRNAs plus miR- 145 correlated with nadir CD4+ T cell count. Discussion: No associations with mortality were found with any circulating miRNA studied. These results cast doubt onto the effectiveness of circulating miRNA as early predictors of mortality or the major underlying diseases that contribute to mortality in participants treated for HIV-1 infection

Development and Validation of a Risk Score for Chronic Kidney Disease in HIV Infection Using Prospective Cohort Data from the D:A:D Study

Ristola M. on työryhmien DAD Study Grp ; Royal Free Hosp Clin Cohort ; INSIGHT Study Grp ; SMART Study Grp ; ESPRIT Study Grp jäsen.Background Chronic kidney disease (CKD) is a major health issue for HIV-positive individuals, associated with increased morbidity and mortality. Development and implementation of a risk score model for CKD would allow comparison of the risks and benefits of adding potentially nephrotoxic antiretrovirals to a treatment regimen and would identify those at greatest risk of CKD. The aims of this study were to develop a simple, externally validated, and widely applicable long-term risk score model for CKD in HIV-positive individuals that can guide decision making in clinical practice. Methods and Findings A total of 17,954 HIV-positive individuals from the Data Collection on Adverse Events of Anti-HIV Drugs (D:A:D) study with >= 3 estimated glomerular filtration rate (eGFR) values after 1 January 2004 were included. Baseline was defined as the first eGFR > 60 ml/min/1.73 m2 after 1 January 2004; individuals with exposure to tenofovir, atazanavir, atazanavir/ritonavir, lopinavir/ritonavir, other boosted protease inhibitors before baseline were excluded. CKD was defined as confirmed (>3 mo apart) eGFR In the D:A:D study, 641 individuals developed CKD during 103,185 person-years of follow-up (PYFU; incidence 6.2/1,000 PYFU, 95% CI 5.7-6.7; median follow-up 6.1 y, range 0.3-9.1 y). Older age, intravenous drug use, hepatitis C coinfection, lower baseline eGFR, female gender, lower CD4 count nadir, hypertension, diabetes, and cardiovascular disease (CVD) predicted CKD. The adjusted incidence rate ratios of these nine categorical variables were scaled and summed to create the risk score. The median risk score at baseline was -2 (interquartile range -4 to 2). There was a 1: 393 chance of developing CKD in the next 5 y in the low risk group (risk score = 5, 505 events), respectively. Number needed to harm (NNTH) at 5 y when starting unboosted atazanavir or lopinavir/ritonavir among those with a low risk score was 1,702 (95% CI 1,166-3,367); NNTH was 202 (95% CI 159-278) and 21 (95% CI 19-23), respectively, for those with a medium and high risk score. NNTH was 739 (95% CI 506-1462), 88 (95% CI 69-121), and 9 (95% CI 8-10) for those with a low, medium, and high risk score, respectively, starting tenofovir, atazanavir/ritonavir, or another boosted protease inhibitor. The Royal Free Hospital Clinic Cohort included 2,548 individuals, of whom 94 individuals developed CKD (3.7%) during 18,376 PYFU (median follow-up 7.4 y, range 0.3-12.7 y). Of 2,013 individuals included from the SMART/ESPRIT control arms, 32 individuals developed CKD (1.6%) during 8,452 PYFU (median follow-up 4.1 y, range 0.6-8.1 y). External validation showed that the risk score predicted well in these cohorts. Limitations of this study included limited data on race and no information on proteinuria. Conclusions Both traditional and HIV-related risk factors were predictive of CKD. These factors were used to develop a risk score for CKD in HIV infection, externally validated, that has direct clinical relevance for patients and clinicians to weigh the benefits of certain antiretrovirals against the risk of CKD and to identify those at greatest risk of CKD.Peer reviewe

Elucidation of soft tissue flap histologic margins within a canine vocal fold

Summary. Background: Histologic identification of implanted soft tissues in experimental animal models can be challenging, as donor tissue often strongly resembles the recipient bed. We have encountered this dilemma following implantation of a Composite Thyroid Ala Perichondrium flap (CTAP) into a vocal fold. The CTAP procedure is the first to utilize a vascularized flap for vocal fold reconstruction, making data to confirm or refute its viability critical. The current study evaluated several tissue stains to define precisely the histologic margins of CTAPs at two weeks post-implantation in a canine model. Methods: Initial testing exposed canine cadaveric tissues to four stains (tattoo ink, Congo red, 4’6- diamidino-2-phenylindole, and henna) across four time periods. Tattoo ink alone withstood histologic processing. An exposure of 1 minute adequately delineated CTAP boundaries. The study concluded with a canine in vivo evaluation of a CTAP exposed to tattoo ink for 1 minute. After a two-week recovery period, vocal folds were harvested and evaluated histologically. Results: Tattoo ink proved to be a safe and effective histologic marker in vivo, where the histologic margins of the implanted CTAP were clearly demarcated by a thin band of tattoo ink, soft tissue reactions were minimal, and interference with standard, special, or immunohistochemical stain assessments did not occur. Conclusions: Tattoo ink provides a reliable means of demarcating a CTAP within a vocal fold and demonstrated that CTAPs survive transplantation. Further, tattoo ink demarcation may serve as a useful histologic marker for those wishing to assess tissue implants in other in vivo models

Local vascularized flaps for augmentation of reinke's space

[[abstract]]Objectives/Hypothesis: The purpose of this study is to describe and test a novel surgical strategy for augmentation of Reinke's space using vascularized flaps: a thyroid ala perichondrium flap (TAP) and a composite thyroid ala perichondrium flap (CTAP) from the anterior larynx. We hypothesized that these specially designed vascularized flaps would remain viable once inset into the lamina propria, and that they would not disrupt rheologic, biomechanical, and histologic properties of the native vocal fold. Study Design: Experimental. In vivo canine model. Methods: The length and volume of test flaps harvested in six adult human cadaveric larynges were analyzed to determine suitability for use in augmentation in the lamina propria. Also, 12 beagles randomly underwent unilateral placement of either TAP or CTAP, which were designed in accordance with the human adult cadaveric experiments. Flap perfusion was measured before and after harvest with laser Doppler. After 1 month, the beagles were humanely sacrificed and their larynges subjected to aerodynamic and acoustic evaluation using an excised larynx apparatus. The vocal fold lamina propria of four larynges—two TAP and two CTAP—underwent rheologic evaluation using a simple‐shear rheometer. The remaining eight larynges underwent quantitative histologic and immunohistochemical evaluation. The survival and complication (swallowing, airway, local wound) rates of all dogs were noted. Results: Initial studies with adult human cadaveric larynges established that TAP and CTAP possessed length and volume greater than native lamina propria. In the canine experiments, the perfusion change in the flaps was similar between flap groups. The damping ratio (ζ), dynamic viscosity (η′), elastic shear modulus (G′), and viscous shear modulus (G″) of treated and untreated native vocal folds were not statistically different. The glottic function measures of vocal efficiency, laryngeal resistance, jitter, shimmer, and harmonics‐to‐noise ratio (HNR) of treated and normal larynges were not statistically different. Similarly, the values for collagen, elastin, and glycosaminoglycans (GAGs) in treated and untreated vocal folds were not statistically different. Also, neither neochrondrogenesis nor neoosteogenesis was detected in any treated vocal fold. The values for vascular and cellular proliferation in treated and untreated vocal folds were not statistically different. All test dogs survived and had no complications related to swallowing, airway distress, or the local wound. Conclusions: The test flaps described and tested in this study appear to have conceptually attractive features for augmentation of Reinke's space. When placed in an in vivo setting TAP and CTAP did not reveal unfavorable vascular, rheologic, aerodynamic, acoustic, or histologic characteristics. There was no unanticipated morbidity or mortality to the test animals. Long‐term viability of these flaps is unknown. TAP and CTAP may open novel pathways for correction of glottic defects and may offer crossover opportunities with tissue engineering techniques