Scintillation characteristics of the EJ-299-02H scintillator.

A study of the dead layer thickness and quenching factor of a plastic scintillator for use in ultracold neutron (UCN) experiments is described. Alpha spectroscopy was used to determine the thickness of a thin surface dead layer to be 630 ± 110 nm. The relative light outputs from the decay of 241Am and Compton scattering of electrons were used to extract Birks' law coefficient, yielding a kB value of 0.087 ± 0.003 mm/MeV, consistent with some previous reports for other polystyrene-based scintillators. The results from these measurements are incorporated into the simulation to show that an energy threshold of (∼9 keV) can be achieved for the UCNProBe experiment. This low threshold enables high beta particle detection efficiency and the indirect measurement of UCN. The ability to make the scintillator deuterated, accompanied by its relatively thin dead layer, gives rise to unique applications in a wide range of UCN experiments, where it can be used to trap UCN and detect charged particles in situ.

Airway Management for Emergency Spinal Epidural Hematoma Evacuation With Awake Spine Surgery: Case Report and Literature Review.

BACKGROUND: Postoperative spinal epidural hematomas (pSEHs) are a rare complication of microdiscectomy surgery. The hematoma may be unnoticed intraoperatively, but timely treatment may prevent permanent neurologic impairment. Airway management in patients with a full stomach is generally performed with rapid sequence intubation and general anesthesia. Awake spine surgery without intravenous analgesia or sedation may be beneficial in patients with a full stomach who are at higher risk for pulmonary aspiration with general anesthesia due to a loss of non-per-oral (NPO) status. The authors propose that it can also be performed in cases of urgent/emergent postsurgical epidural hematoma evacuation. METHODS: We present the airway management of a 41-year-old man who underwent a minimally invasive microdiscectomy with normal strength immediately after surgery but developed progressive weakness with right foot dorsiflexion, right extensor hallucis longus muscle weakness, and progressive right lower extremity ascending numbness over the course of the first 2 hours after surgery due to an epidural hematoma. RESULTS: The patient underwent urgent awake epidural hematoma evacuation with a spinal anesthetic. Afterward, the patient recovered neurological function and was discharged the following morning. CLINICAL RELEVANCE: pSEHs are a rare complication of microdiscectomy surgery. The purpose of this article is to describe the novel use of awake spine surgery in emergent epidural hematoma evacuation and demonstrate its feasibility. CONCLUSIONS: In emergencies, when a patient is not NPO, awake spine surgery can safely be performed with no sedation, ensuring the patient can protect their airway and avoid the risk of aspiration.

Improved Neutron Lifetime Measurement with UCNτ.

We report an improved measurement of the free neutron lifetime τ_{n} using the UCNτ apparatus at the Los Alamos Neutron Science Center. We count a total of approximately 38×10^{6} surviving ultracold neutrons (UCNs) after storing in UCNτ's magnetogravitational trap over two data acquisition campaigns in 2017 and 2018. We extract τ_{n} from three blinded, independent analyses by both pairing long and short storage time runs to find a set of replicate τ_{n} measurements and by performing a global likelihood fit to all data while self-consistently incorporating the ß-decay lifetime. Both techniques achieve consistent results and find a value τ_{n}=877.75±0.28_{stat}+0.22/-0.16_{syst} s. With this sensitivity, neutron lifetime experiments now directly address the impact of recent refinements in our understanding of the standard model for neutron decay.

Ultracold neutron properties of the Eljen-299-02D deuterated scintillator.

In this paper, we report studies of the Fermi potential and loss per bounce of ultracold neutrons (UCNs) on a deuterated scintillator (Eljen-299-02D). These UCN properties of the scintillator enable its use in a wide variety of applications in fundamental neutron research.

Perceived Built Environment and Physical Limitations: Race Contrasts in Historically Lower-Income African American Neighborhoods.

This study uses primary data from a community-based random sample of adults in historically lower-income African American (or Black) neighborhoods in Atlanta, Georgia (N = 352). The aim was to investigate whether there are race differences in perceived neighborhood conditions/amenities, and the potential conditional effect of race on the relationship between the perceived built environment and physical limitations. Findings indicate significant race differences in the perceived built environment and that the relationship between the perceived built environment and physical limitations is conditioned by race, whereby Whites experience greater physical health benefits from more neighborhood conditions/amenities than African Americans.

Measurement of the neutron lifetime using a magneto-gravitational trap and in situ detection.

The precise value of the mean neutron lifetime, τn, plays an important role in nuclear and particle physics and cosmology. It is used to predict the ratio of protons to helium atoms in the primordial universe and to search for physics beyond the Standard Model of particle physics. We eliminated loss mechanisms present in previous trap experiments by levitating polarized ultracold neutrons above the surface of an asymmetric storage trap using a repulsive magnetic field gradient so that the stored neutrons do not interact with material trap walls. As a result of this approach and the use of an in situ neutron detector, the lifetime reported here [877.7 ± 0.7 (stat) +0.4/-0.2 (sys) seconds] does not require corrections larger than the quoted uncertainties.

A new method for measuring the neutron lifetime using an in situ neutron detector.

In this paper, we describe a new method for measuring surviving neutrons in neutron lifetime measurements using bottled ultracold neutrons (UCN), which provides better characterization of systematic uncertainties and enables higher precision than previous measurement techniques. An active detector that can be lowered into the trap has been used to measure the neutron distribution as a function of height and measure the influence of marginally trapped UCN on the neutron lifetime measurement. In addition, measurements have demonstrated phase-space evolution and its effect on the lifetime measurement.

Post-traumatic stress symptoms in children and adolescents with chronic pain: A topical review of the literature and a proposed framework for future research.

BACKGROUND AND OBJECTIVE: The co-occurrence of chronic pain and post-traumatic stress symptoms (PTSS) and post-traumatic stress disorder (PTSD) has gained increasing research attention. Studies on associations among pain and PTSS or PTSD in youth have largely been conducted in the context of acute injury or trauma. Less is known about the risk for co-occurrence with paediatric chronic pain. In this review, we (1) propose a conceptual framework to outline factors salient during childhood that may be associated with symptom severity, co-occurrence and mutual maintenance, (2) present relevant literature on PTSS in youth with acute and chronic pain and identify research gaps and (3) provide recommendations to guide paediatric research examining shared symptomatology. DATABASES AND DATA TREATMENT: Electronic databases (PubMed and Google Scholar) were used to identify relevant articles using the search terms 'child, adolescent, paediatric, chronic pain, acute pain, post-traumatic stress symptoms and post-traumatic stress disorder'. Studies were retrieved and reviewed based on relevance to the topic. RESULTS: Our findings revealed that existing biobehavioural and ecological models of paediatric chronic pain lack attention to traumatic events or the potential development of PTSS. Paediatric studies are also limited by lack of a conceptual framework for understanding the prevalence, risk and trajectories of PTSS in youth with chronic pain. CONCLUSIONS: Our new developmentally informed framework highlights individual symptoms and shared contextual factors that are important when examining potential associations among paediatric chronic pain and PTSS. Future studies should consider bidirectional and mutually maintaining associations, which will be aided by prospective, longitudinal designs. WHAT DOES THIS REVIEW ADD?: This review presents relevant literature on pain and PTSS in youth and proposes a conceptual framework to examine factors salient during childhood that may be associated with symptom severity, comorbidity and mutual maintenance of chronic pain and PTSS in paediatric populations. We highlight dynamic factors that may change across children's development and provide recommendations to guide paediatric research examining potential associations among PTSS and chronic pain.

A slow neutron polarimeter for the measurement of parity-odd neutron rotary power.

We present the design, description, calibration procedure, and an analysis of systematic effects for an apparatus designed to measure the rotation of the plane of polarization of a transversely polarized slow neutron beam as it passes through unpolarized matter. This device is the neutron optical equivalent of a crossed polarizer/analyzer pair familiar from light optics. This apparatus has been used to search for parity violation in the interaction of polarized slow neutrons in matter. Given the brightness of existing slow neutron sources, this apparatus is capable of measuring a neutron rotary power of dϕ/dz = 1 × 10(-7) rad/m.

Communication resources for obesity prevention among African American and Latino residents in an urban neighborhood.

African Americans and Latinos are at disproportionately high risk for obesity and for the chronic conditions and diseases associated with it. This study uses communication infrastructure theory to explore how connections to neighborhood communication resources and communication with family members can affect residents' regular exercise and healthy eating behaviors-two of the most direct strategies for achieving or maintaining a healthy weight. Regression analyses revealed that connections to the neighborhood storytelling network and family interaction predicted residents' regular exercise and that family interaction had the strongest effect on the likelihood of exercising regularly. Family interaction was the only independent variable that predicted residents' daily intake of fruits and vegetables. Implications of these findings for community health programs and theory development are discussed.

Prevalence and significance of CYP2C19*2 and CYP2C19*17 alleles in a New Zealand acute coronary syndrome population.

BACKGROUND: High on-treatment platelet reactivity has been associated with poor outcomes following acute coronary syndromes (ACS). Both the loss of function CYP2C19*2 allele and the gain of function CYP2C19*17 allele along with a range of clinical characteristics have been associated with variation in the response to clopidogrel. AIM: The study aims to examine the frequency of CYP2C19 variants and understand the factors associated with on-treatment platelet reactivity in a New Zealand ACS population. METHODS: We prospectively enrolled 312 ACS patients. We collected clinical characteristics and measured on-treatment platelet reactivity using two validated point-of-care assays, VerifyNow and Multiplate. DNA was extracted and CYP2C19*2 and *17 alleles were identified using real-time polymerase chain reaction. RESULTS: CYP2C19*2 or CYP2C19*17 alleles were observed in 101 (32%) and 106 (34%) of patients, respectively, with significant differences in distribution by ethnicity. In Maori and Pacific Island patients, 47% (confidence interval (CI) 31-63%) had CYP2C19*2 and 11% (CI 4-19%) CYP2C19*17 compared with 26% (CI 19-32%) and 41% (CI 32-49%) in white people. Carriage of CYP2C19*2 alleles was associated with higher levels of platelet reactivity measured by either assay, but we observed no relationship between platelet reactivity and CYP2C19*17. In multivariate analysis diabetes, clopidogrel dose and CYP2C19*2 status were all significant independent predictors of platelet reactivity. CONCLUSIONS: Both CYP2C19*2 and *17 were common in a New Zealand ACS population, with CYP2C19*2 observed in almost half the Maori and Pacific Island patients. CYP2C19*2, diabetes and clopidogrel dose were independent contributors to on-treatment platelet reactivity.

Communicative social capital and collective efficacy as determinants of access to health-enhancing resources in residential communities.

This article contributes to the burgeoning literature on the social determinants of health disparities. The authors investigate how communication resources and collective efficacy, independently and in combination, shape residents' access to health enhancing resources (including healthcare services, sources of healthier food options, and public recreation spaces) in their communities. Using random digit dial telephone survey data from 833 residents of South Los Angeles communities the authors show that communicative social capital-that is, an information and problem-solving resource that accrues to residents as they become more integrated into their local communication network of neighbors, community organizations, and local media-plays a significant role in access to health resources. This relationship is complicated by individuals' health insurance and health status, as communicative social capital magnifies the sense of absence of resources for those who are in worse health and lack insurance. Communicative social capital builds collective efficacy, which is positively related to access to health-enhancing resources, but it also mediates the negative relationship between communicative social capital and access to health resources. Residents with richer stores of communicative social capital and collective efficacy report better access to health resources. The authors conclude with a discussion of implications of these findings and suggestions for future research.

Prognostic significance of tricuspid annular displacement in normotensive patients with acute symptomatic pulmonary embolism.

BACKGROUND: Tricuspid annular plane systolic excursion (TAPSE) is an emerging prognostic indicator in patients with acute symptomatic pulmonary embolism (PE). METHODS AND RESULTS: We prospectively examined 782 normotensive patients with PE who underwent echocardiography in a multicenter study. As compared with patients with a TAPSE of > 1.6 cm, those with a TAPSE of ≤ 1.6 cm had increased systolic pulmonary artery pressure (53.7 ± 16.7 mmHg vs. 40.0 ± 15.5 mmHg, P < 0.001), right ventricle (RV) end-diastolic diameter (3.5 ± 0.8 cm vs. 3.0 ± 0.6 cm, P < 0.001), and RV to left ventricle end-diastolic diameter ratio (1.0 ± 0.3 vs. 0.8 ± 0.2, P < 0.001), and a higher prevalence of RV free wall hypokinesis (68% vs. 11%, P < 0.001). Patients with a TAPSE of ≤ 1.6 cm at the time of PE diagnosis were significantly more likely to die from any cause (hazard ratio [HR] 2.3; 95% confidence interval [CI] 1.2-4.7; P = 0.02) and from PE (HR 4.4; 95% CI 1.3-15.3; P = 0.02) during follow-up. In an external validation cohort of 1326 patients with acute PE enrolled in the international multicenter Registro Informatizado de la Enfermedad TromboEmbólica, a TAPSE of ≤ 1.6 cm remained a significant predictor of all-cause mortality (HR 2.1; 95% CI 1.3-3.2; P = 0.001) and PE-specific mortality (HR 2.5; 95% CI 1.2-5.2; P = 0.01). CONCLUSIONS: In normotensive patients with PE, TAPSE reflects right ventricular function. For these patients, TAPSE is independently predictive of survival.

Performance of the Los Alamos National Laboratory spallation-driven solid-deuterium ultra-cold neutron source.

In this paper, we describe the performance of the Los Alamos spallation-driven solid-deuterium ultra-cold neutron (UCN) source. Measurements of the cold neutron flux, the very low energy neutron production rate, and the UCN rates and density at the exit from the biological shield are presented and compared to Monte Carlo predictions. The cold neutron rates compare well with predictions from the Monte Carlo code MCNPX and the UCN rates agree with our custom UCN Monte Carlo code. The source is shown to perform as modeled. The maximum delivered UCN density at the exit from the biological shield is 52(9) UCN/cc with a solid deuterium volume of ~1500 cm(3).

Frozen blood products: clinically effective and potentially ideal for remote Australia.

The development of effective cryopreservation techniques for both red blood cells and platelets, which maintain ex vivo biological activity, in combination with frozen plasma, provides for a unique blood banking strategy. This technology greatly enhances the storage life of these products. The rationale and potential advantages of using cryopreservation techniques for the provision of blood products to remote and military environments have been effectively demonstrated in several conflicts over the last decade. Current haemostatic resuscitation doctrine for the exsanguinating patient supports the use of red blood cells, platelets and frozen plasma early in the resuscitation. We believe an integrated fresh-frozen blood bank inventory could facilitate provision of blood products, not only in the military setting but also in regional Australia, by overcoming many logistic and geographical challenges. The processes involved in production and point of care thawing are sufficiently well developed and achievable to make this technology a viable option. The potential limitations of cryopreservation and subsequent product thawing need to be considered if such a strategy is to be developed. A substantial body of international experience using cryopreserved products in remote settings has already been accrued. This experience provides a template for the possible creation of an Australian integrated fresh-frozen blood bank inventory that could conceivably enhance the care of patients in both regional Australia and in the military setting.

Reciprocal longitudinal associations between pain and depressive symptoms in adolescents.

BACKGROUND: Elevated depressive symptoms are common in youth with chronic pain, and pain symptoms are frequent in adolescents with depressive disorders. While studies have identified concurrent associations between pain and depression over time in youth, it is unclear how change in one symptom impacts change in the other symptom. METHODS: This three-time point 12-month longitudinal study examined reciprocal associations among pain and depression in a clinical sample of adolescents (12-18) diagnosed with chronic pain (n = 55) or a depressive disorder (n = 40). Mixed-effects multivariate models were used to test if changes over a preceding time interval predicted symptom severity at subsequent time points. Study group, age, sex, race, baseline pain intensity and baseline depressive symptoms were included as covariates. RESULTS: Generalized estimating equations revealed that pain and depressive symptoms were significantly associated over time (ß = 1.54; p < 0.001). As hypothesized, changes in pain were associated with subsequent depressive symptoms (ß = 1.16; p < 0.001). Conversely, changes in depressive symptoms predicted subsequent pain (ß = 0.026; p < 0.05), but with a weaker association. In the model predicting pain, an interaction between depressive symptoms and study group emerged (ß = -0.02; p < 0.05), with change in depressive symptoms having the greatest impact on pain in the depressed sample. CONCLUSIONS: Findings extend previous adult research to an adolescent sample showing changes in pain intensity are predictive of subsequent depressive symptoms. In comparison to adult data, changes in depressive symptoms had less impact on subsequent pain in youth. Future research can examine how targeting persistent pain may also aid the treatment of depressive symptoms in adolescents.

When patients are impatient: the communication strategies utilized by emergency department employees to manage patients frustrated by wait times.

Studies have documented the frustrations patients experience during long wait times in emergency departments (EDs), but considerably less research has sought to understand ED staff responses to these frustrations. In-depth interviews were conducted with 18 ED social workers, patient navigators, and medical staff members at a large urban hospital regarding their experiences and interpersonal strategies for dealing with frustrated patients. Staff indicated that patients often attribute delays to neglect and do not understand why their health problem is not prioritized. They voiced several strategies for addressing wait time frustrations, including expressing empathy for patients, making patients feel occupied and wait times seem more productive, and educating patients about when health issues should be treated through primary care. All staff members recognized the need for engaging in empathic communication with frustrated patients, but social workers and patient navigators were able to dedicate more time to these types of interactions.

A high-field adiabatic fast passage ultracold neutron spin flipper for the UCNA experiment.

The UCNA collaboration is making a precision measurement of the ß asymmetry (A) in free neutron decay using polarized ultracold neutrons (UCN). A critical component of this experiment is an adiabatic fast passage neutron spin flipper capable of efficient operation in ambient magnetic fields on the order of 1 T. The requirement that it operate in a high field necessitated the construction of a free neutron spin flipper based, for the first time, on a birdcage resonator. The design, construction, and initial testing of this spin flipper prior to its use in the first measurement of A with UCN during the 2007 run cycle of the Los Alamos Neutron Science Center's 800 MeV proton accelerator is detailed. These studies determined the flipping efficiency of the device, averaged over the UCN spectrum present at the location of the spin flipper, to be ̅ε=0.9985(4).