The design of a line velocity interferometer for any reflector for inertial confinement experiments on the Z-machine

A line VISAR (Velocity Interferometer System for Any Reflector) has been designed and commissioned at the Sandia National Laboratory's Z-machine. The instrument consists of an F/2 collection system, beam transport, and an interferometer table that contains two Mach-Zehnder type interferometers and an eight channel Gated Optical Imaging (GOI) system. The VISAR probe laser operates at the 532 nm wavelength, and the GOI bandpass is 540-600 nm. The output of each interferometer is passed to an optical streak camera with four selectable sweep speeds. The system is designed with three interchangeable optics modules to select a full field of view of 1 mm, 2 mm, or 4 mm. The optical beam transport system connects the target image plane to the interferometers and the gated optical imagers. The target is integrated into a sacrificial final optics assembly that is integral to the transport beamline.

73 Is There A Real Relationship Between Body Mass Index and Vasovagal Syncope or is it Just Anecdote?

Introduction

Syncope is characterised by global cerebral hypoperfusion rapidly causing a transient loss of consciousness with loss of voluntary muscle tone and a subsequent spontaneous, prompt and complete recovery. It is often caused by Neurally mediated reflex syncope syndromes of which Vasovagal syncope (VVS) is the commonest form. The prodromal symptoms of VVS are explained by circulatory alterations (vasodilatation and bradycardia) and autonomic activation. Whilst many triggers and risk factors for such alterations are recognised, they are incompletely understood. Anecdotally, being “young and thin” is a risk factor but there is little published data evaluating the relationship between body weight and VVS. Whilst VVS can often be diagnosed on clinical history alone, further evaluation is warranted in some patients. The validated test to assess susceptibility to VVS is the head-up-tilt table (HUT) test. We set out to evaluate the relationship between Body Mass Index (BMI) and the outcome of HUT testing.

Methods

We reviewed the outcomes of 1193 patients attending for HUT testing at the University Hospitals of Leicester between December 2014 and October 2017. The protocol used was a 40 minute passive HUT (70 degree) followed by sublingual nitroglyserin. The parameters of height, weight, gender and test outcome were recorded prospectively and interrogated retrospectively.

Results

Of the 1193 patients, the passive HUT test was positive for VVS in 293 patients. These patients were then sub-grouped by BMI as set out in the table. The chances of VVS, as diagnosed by HUT testing are almost doubled in those with a (clinically underweight) BMI range 16-20. (p value 0.002-0.001)

Discussion

The presented data supports the anecdotal experience of many clinicians: that low BMI may be associated with an increased tendency to VVS. The physiological basis for this (if it is real) is not understood and requires further evaluation since it may have implications for future management strategies. Larger studies are required to further analyse this relationship to determine if BMI is an independent predictor or risk factor for VVS.

Investigation of the fine structure of antihydrogen

At the historic Shelter Island Conference on the Foundations of Quantum Mechanics in 1947, Willis Lamb reported an unexpected feature in the fine structure of atomic hydrogen: a separation of the 2S1/2 and 2P1/2 states1. The observation of this separation, now known as the Lamb shift, marked an important event in the evolution of modern physics, inspiring others to develop the theory of quantum electrodynamics2-5. Quantum electrodynamics also describes antimatter, but it has only recently become possible to synthesize and trap atomic antimatter to probe its structure. Mirroring the historical development of quantum atomic physics in the twentieth century, modern measurements on anti-atoms represent a unique approach for testing quantum electrodynamics and the foundational symmetries of the standard model. Here we report measurements of the fine structure in the n = 2 states of antihydrogen, the antimatter counterpart of the hydrogen atom. Using optical excitation of the 1S-2P Lyman-α transitions in antihydrogen6, we determine their frequencies in a magnetic field of 1 tesla to a precision of 16 parts per billion. Assuming the standard Zeeman and hyperfine interactions, we infer the zero-field fine-structure splitting (2P1/2-2P3/2) in antihydrogen. The resulting value is consistent with the predictions of quantum electrodynamics to a precision of 2 per cent. Using our previously measured value of the 1S-2S transition frequency6,7, we find that the classic Lamb shift in antihydrogen (2S1/2-2P1/2 splitting at zero field) is consistent with theory at a level of 11 per cent. Our observations represent an important step towards precision measurements of the fine structure and the Lamb shift in the antihydrogen spectrum as tests of the charge-parity-time symmetry8 and towards the determination of other fundamental quantities, such as the antiproton charge radius9,10, in this antimatter system.

Liquid Chromatographic Determination of Glyphosate in Water-Soluble Granular Formulations: Collaborative Study

A liquid chromatographic (LC) method for the determination of glyphosate in various water-soluble granular formulations was tested by 28 laboratories. Samples were dissolved in mobile phase and injected directly into an LC system with a 25 cm SAX column and a mobile phase of 96% aqueous buffer solution, 0.0062M KH2PO4, and 4% methanol. Detection was by UV absorption at 195 nm. Manual or automated injections were made via fixed-volume loops. Calculations were based on peak area comparisons with external standards. The collaborative study analyzed 5 matched pairs of 4 water-soluble granular formulations, with one determination per sample. The study generated 138 matched pairs, which were analyzed by using the AOAC spreadsheet and Youden’s matched-pair calculations. Coefficients of variation for the 4 formulations ranged from 0.65 to 1.37%. The LC method for the determination of glyphosate in water-soluble granular formulations has been adopted first action by AOAC INTERNATIONAL.

Determination of Lead in Wine by Graphite Furnace Atomic Absorption Spectrophotometry: Interlaboratory Study

An interlaboratory study of a graphite furnace atomic absorption spectrophotometry (GFAAS) method for the determination of lead in wine was conducted. Seventeen laboratories from France, United States, and the United Kingdom, using a variety of GFAAS instruments, took part in the study. The method incorporated a novel matrix-matching procedure to minimize matrix effects between standards and samples. Six wine test materials were prepared and sent to participants as 12 blind duplicate or split level samples. There was good agreement between results obtained from participants and target values (24–279 μg/L) obtained with an inductively coupled plasma-mass spectrometry method. The precision of the GFAAS method was well within the range predicted by the Horwitz equation for the 6 test materials analyzed. Repeatability standard deviations ranged from 3 to 17%. Reproducibility standard deviations were in the range of 10 to 30%. The method is recommended for use for official purposes.

P371 Right ventricle end-systolic remodeling index in patients with atrial septal defect and severe pulmonary arterial hypertension

Background Outcome of patients with atrial septal defect (ASD) and severe pulmonary arterial hypertension (PAH) relates to right ventricular (RV) function.

Magnetic resonance imaging (MRI) remains the gold standard for evaluating the RV function but it is not used routinely. We investigated the relationship between MRI and multiple echocardiography parameters, including the Right Ventricle End-Systolic Remodeling Index (RVESRI), a new prognostic marker in patients with PAH.

Methods 23 patients with ASD and severe PAH (median age 49y.o.[39-59], Sp0 2 92% [90-95], WHO functional class II or III, mean pulmonary artery pressure 51mmHg [40-59]) were included between 2014 and 2018. All patients underwent MRI and echocardiography assessment. Echocardiographic measurements of RV remodeling and function included TAPSE, RV fractional area change (RVFAC), peak systolic velocity of the tricuspid valve (S’TV), right atrial (RA) area, RV strain, Systolic to diastolic ratio, eccentricity index and RVESRI, defined by septum length divided by lateral wall length (Figure 1). Pericardial effusion was noted.

Results Median RV ejection fraction (EF) evaluated with MRI was 46 % [34-59]. RV dysfunction (RVEF < 45%) was observed in 43% of patients. Median RVFAC and

RVESRI were 29.6%[23-34] and 1.6[1.4-1.7] respectively. By spearman correlation, RVFAC and RVESRI were significantly correlated to RVEF (Rho 0.62, p < 0.007 and

Rho -0.51,p < 0.02 respectively). By linear regression, RVFAC and RVESRI were also correlated to RVEF (R 2 =0.36, p < 0.003 and R 2 =0.34, p < 0.08). Pericardial effusion was associated with RV dysfunction (p< 0.008) and a lower RVFAC (p < 0.01). TAPSE, S’TV and RV strain were not correlated with RVEF.

Conclusion RVFAC, RVESRI and pericardial effusion were markers of RV dysfunction in patients with ASD and severe PAH. RVESRI appears as a simple and reliable parameter for follow-up. Its prognostic value in patients with CHD remains to be demonstrated.

Personal and Neighborhood Attributes Associated with Cervical and Colorectal Cancer Screening in an Urban African American Population

Introduction

Assessing individual social determinants of health in primary care might be complemented by consideration of population attributes in patients’ neighborhoods. We studied associations between cervical and colorectal cancer screening and neighborhood attributes among an African American population in Philadelphia.

Methods

We abstracted demographic and cancer screening information from records of patients seen during 2006 at 3 federally qualified health centers and characterized patients’ census tracts of residence by using census, survey, and other data to define population metrics for poverty, racial segregation, educational attainment, social capital, neighborhood safety, and violent crime. We used generalized estimating equations to obtain adjusted relative risks of screening associated with individual and census tract attributes.

Results

Among 1,708 patients for whom colorectal cancer screening was recommended, screening was up to date for 41%, and among 4,995 women for whom cervical cancer screening was recommended, screening was up to date for 75%. After controlling for age, sex (for colorectal cancer screening), insurance coverage, and clinic site, people living in the most racially segregated neighborhoods were nearly 10% more likely than others to be unscreened for colorectal cancer. Other census tract population attributes were not associated with differences in screening levels for either cancer.

Conclusions

The association between lower rates of colorectal cancer screening and neighborhood racial segregation is consistent with known barriers to colonoscopy among African Americans combined with effects of segregation on health-related behaviors. Recognition of the association between segregation and lower colorectal cancer screening rates might be useful in informing and targeting community outreach to improve screening.

Identifying neighborhood characteristics associated with diabetes and hypertension control in an urban African-American population using geo-linked electronic health records

For health care providers, information on community-level social determinants of health is most valuable when it is specific to the populations and health outcomes for which they are responsible. Diabetes and hypertension are highly prevalent conditions whose management requires an interplay of clinical treatment and behavioral modifications that may be sensitive to community conditions. We used geo-linked electronic health records from 2016 of African American patients of a network of federally qualified health centers in Philadelphia, PA to examine cross-sectional associations between characteristics of patients' residential neighborhoods and hypertension and diabetes control (n = 1061 and n = 2633, respectively). Hypertension and diabetes control were defined to align with the Health Resources and Services Administration (HRSA) Uniform Data System (UDS) reporting requirements for HRSA-funded health centers. We examined associations with nine measures of neighborhood socioeconomic status (poverty, education, deprivation index), social environment (violent crime, perceived safety and social capital, racial segregation), and built environment (land-use mix, intersection density). In demographics-adjusted log-binomial regression models accounting for neighborhood-level clustering, poor diabetes and hypertension control were more common in highly segregated neighborhoods (i.e., high proportion of African American residents relative to the mean for Philadelphia; prevalence ratio = 1.27 [1.02-1.57] for diabetes, 1.22 [1.12-1.33] for hypertension) and less common in more walkable neighborhoods (i.e., higher retail land use). Neighborhood deprivation was also weakly associated with poor hypertension control. An important consideration in making geographic information actionable for providers is understanding how specific community-level determinants affect the patient population beyond individual-level determinants.

Abstract P3-09-05: Withdrawn

This abstract was withdrawn by the authors.

Citation Format: Chakladar M, Nair MG, Prabhu JS, Cohen S, Srinivas ST, Lingadahalli SS. Withdrawn [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-09-05.