Invariant states and rates of Convergence for a critical fluid model of a processor sharing queue

This paper contains an asymptotic analysis of a fluid model for a heavily loaded processor sharing queue. Specifically, we consider the behavior of solutions of critical fluid models as time approaches \infty. The main theorems of the paper provide sufficient conditions for a fluid model solution to converge to an invariant state and, under slightly more restrictive assumptions, provide a rate of convergence. These results are used in a related work by Gromoll for establishing a heavy traffic diffusion approximation for a processor sharing queue

A Scientist's Guide to Achieving Broader Impacts through K-12 STEM Collaboration.

The National Science Foundation and other funding agencies are increasingly requiring broader impacts in grant applications to encourage US scientists to contribute to science education and society. Concurrently, national science education standards are using more inquiry-based learning (IBL) to increase students' capacity for abstract, conceptual thinking applicable to real-world problems. Scientists are particularly well suited to engage in broader impacts via science inquiry outreach, because scientific research is inherently an inquiry-based process. We provide a practical guide to help scientists overcome obstacles that inhibit their engagement in K-12 IBL outreach and to attain the accrued benefits. Strategies to overcome these challenges include scaling outreach projects to the time available, building collaborations in which scientists' research overlaps with curriculum, employing backward planning to target specific learning objectives, encouraging scientists to share their passion, as well as their expertise with students, and transforming institutional incentives to support scientists engaging in educational outreach

Effects of hypoxic-ischemic encephalopathy and whole-body hypothermia on neonatal auditory function: a pilot study.

We assessed the effects of hypoxic-ischemic encephalopathy (HIE) and whole-body hypothermia therapy on auditory brain stem evoked responses (ABRs) and distortion product otoacoustic emissions (DPOAEs). We performed serial assessments of ABRs and DPOAEs in newborns with moderate or severe HIE, randomized to hypothermia ( N = 4) or usual care ( N = 5). Participants were five boys and four girls with mean gestational age (standard deviation) of 38.9 (1.8) weeks. During the first week of life, peripheral auditory function, as measured by the DPOAEs, was disrupted in all nine subjects. ABRs were delayed but central transmission was intact, suggesting a peripheral rather than a central neural insult. By 3 weeks of age, peripheral auditory function normalized. Hypothermia temporarily prolonged the ABR, more so for waves generated higher in the brain stem but the effects reversed quickly on rewarming. Neonatal audiometric testing is feasible, noninvasive, and capable of enhancing our understanding of the effects of HIE and hypothermia on auditory function

Changes in the PQRST intervals and heart rate variability associated with rewarming in two newborns undergoing hypothermia therapy.

BACKGROUND: Little is known about the effects of hypothermia therapy and subsequent rewarming on the PQRST intervals and heart rate variability (HRV) in term newborns with hypoxic-ischemic encephalopathy (HIE). OBJECTIVES: This study describes the changes in the PQRST intervals and HRV during rewarming to normal core body temperature of 2 newborns with HIE after hypothermia therapy. METHODS: Within 6 h after birth, 2 newborns with HIE were cooled to a core body temperature of 33.5 degrees C for 72 h using a cooling blanket, followed by gradual rewarming (0.5 degrees C per hour) until the body temperature reached 36.5 degrees C. Custom instrumentation recorded the electrocardiogram from the leads used for clinical monitoring of vital signs. Generalized linear mixed models were calculated to estimate temperature-related changes in PQRST intervals and HRV. Results: For every 1 degrees C increase in body temperature, the heart rate increased by 9.2 bpm (95% CI 6.8-11.6), the QTc interval decreased by 21.6 ms (95% CI 17.3-25.9), and low and high frequency HRV decreased by 0.480 dB (95% CI 0.052-0.907) and 0.938 dB (95% CI 0.460-1.416), respectively. CONCLUSIONS: Hypothermia-induced changes in the electrocardiogram should be monitored carefully in future studies

Determining the shape of a supernova explosion

Spectropolarimetry, a technique that determines the fraction of light from a polarized source as a function of wavelength can help astronomers determine the geometry of a supernova explosion. The spectrum of these objects are a combination of an underlying continuum and superposed absorption and/or emission features. Low degrees of polarization (~0.2-0.3%) across the continuum with higher detections across some spectral features (~1-2%) indicate that a particular explosion is relatively spherical in nature, but some of the ejecta has been expelled in a clumpy manner. It is possible to determine how the star exploded by comparing the evolution of this polarization over time to theoretical explosion models. We present the multi-epoch observations of 2014J, a supernova with very little overall asymmetry as revealed by low continuum polarization measurements. However, a polarization detection of ~0.5% across the singly-ionized silicon spectral feature indicates that this particular ion has a more complex geometry

Choice of resident costimulatory molecule can influence cell fate in human naïve CD4+ T cell differentiation

With antigen stimulation, naïve CD4+ T cells differentiate to several effector or memory cell populations, and cytokines contribute to differentiation outcome. Several proteins on these cells receive costimulatory signals, but a systematic comparison of their differential effects on naïve T cell differentiation has not been conducted. Two costimulatory proteins, CD28 and ICAM-1, resident on human naïve CD4+ T cells were compared for participation in differentiation. Under controlled conditions, and with no added cytokines, costimulation through either CD3+CD28 or CD3+ICAM-1 induced differentiation to T effector and T memory cells. In contrast, costimulation through CD3+ICAM-1 induced differentiation to Treg cells whereas costimulation through CD3+CD28 did not

Mindfulness-Oriented Recovery Enhancement for Chronic Pain and Prescription Opioid Misuse: Results from an Early Stage Randomized Controlled Trial

Objective: Opioid pharmacotherapy is now the leading treatment for chronic pain, a problem that affects nearly one third of the U.S. population. Given the dramatic rise in prescription opioid misuse and opioid-related mortality, novel behavioral interventions are needed. The purpose of this study was to conduct an early-stage randomized controlled trial of Mindfulness-Oriented Recovery Enhancement (MORE), a multimodal intervention designed to simultaneously target mechanisms underpinning chronic pain and opioid misuse. Method: Chronic pain patients (N = 115; mean age = 48 ± 14 years; 68% female) were randomized to 8 weeks of MORE or a support group (SG). Outcomes were measured at pre- and posttreatment, and at 3-month follow-up. The Brief Pain Inventory was used to assess changes in pain severity and interference. Changes in opioid use disorder status were measured by the Current Opioid Misuse Measure. Desire for opioids, stress, nonreactivity, reinterpretation of pain sensations, and reappraisal were also evaluated. Results: MORE participants reported significantly greater reductions in pain severity (p = .038) and interference (p = .003) than SG participants, which were maintained by 3-month follow-up and mediated by increased nonreactivity and reinterpretation of pain sensations. Compared with SG participants, participants in MORE evidenced significantly less stress arousal (p = .034) and desire for opioids (p = .027), and were significantly more likely to no longer meet criteria for opioid use disorder immediately following treatment (p = .05); however, these effects were not sustained at follow-up. Conclusions: Findings demonstrate preliminary feasibility and efficacy of MORE as a treatment for co-occurring prescription opioid misuse and chronic pain

Zika virus infection in the developing mouse produces dramatically different neuropathology dependent on viral strain

Zika virus (ZIKV) infection during pregnancy has been causally linked to a constellation of neurodevelopmental deformities in the fetus resulting in a disease termed congenital Zika syndrome (CZS). Here we detail how ZIKV infection produces extensive neuropathology in the developing mouse brain and spinal cord of both sexes. Surprisingly, neuropathology differs depending on viral strain with a French Polynesian isolate producing primarily excitotoxicity and a Brazilian isolate being almost exclusively apoptotic but occurring over a prolonged period that is more likely to produce severe hypoplasia. We also show exposure can produce a characteristic pattern of infection that mirrors neuropathology and ultimately results in gross morphological deformities strikingly similar to CZS. This research provides a valuable mouse model mirroring the clinical course of disease that can be used to test potential therapies to improve treatment and gain a better understanding of the disabilities associated with CZS

Limiting Pseudomonas aeruginosa Biofilm Formation Using Cold Atmospheric Pressure Plasma

We investigate the ability to disrupt and limit growth biofilms of Pseudomonas aeruginosa using application of cold atmospheric pressure (CAP) plasma. The effect of the bio-film's exposure to a helium (CAP) jet was assessed at varying time points during biofilm maturation. Results showed that the amount of time during biofilm growth that CAP pressure was applied has a crucial role on the ability of biofilms to mature and recover after CAP exposure. Intervention during the early stages of biofilm formation (0-8 h) results in a 4-5-log reduction in viable bacterial cells (measured at 24 h of incubation) relative to untreated biofilms. However, CAP treatment of biofilm at 12 h and above only results in a 2-log reduction in viable cells. This has potentially important implications for future clinical application of CAP to treat infected wounds